diff --git a/Tests/Fs/Mods/Apache/503.html b/Tests/Fs/Mods/Apache/503.html
new file mode 100644
index 0000000..177f983
--- /dev/null
+++ b/Tests/Fs/Mods/Apache/503.html
@@ -0,0 +1 @@
+Please, call us later.
\ No newline at end of file
diff --git a/Tests/VfsBaseTest.pas b/Tests/VfsBaseTest.pas
index 9ce9ba7..2eb3188 100644
--- a/Tests/VfsBaseTest.pas
+++ b/Tests/VfsBaseTest.pas
@@ -46,8 +46,14 @@ begin
   VfsBase.MapDir(RootDir, RootDir + '\Mods\B', DONT_OVERWRITE_EXISTING);
   VfsBase.MapDir(RootDir, RootDir + '\Mods\A', DONT_OVERWRITE_EXISTING);
   VfsBase.RunVfs(SORT_FIFO);
-  VfsBase.GetVfsDirInfo(RootDir, '*', DirInfo, DirListing);
 
+  VfsBase.PauseVfs;
+  VfsBase.GetVfsDirInfo(RootDir, '*', DirInfo, DirListing);
+  DirListing.Rewind;
+  Check(DirListing.GetDebugDump() = '', 'Virtual directory listing must be empty when VFS is paused. Got: ' + DirListing.GetDebugDump());
+
+  VfsBase.RunVfs(SORT_FIFO);
+  VfsBase.GetVfsDirInfo(RootDir, '*', DirInfo, DirListing);
   DirListing.Rewind;
   Check(DirListing.GetDebugDump() = 'vcredist.bmp'#13#10'eula.1028.txt', 'Invalid virtual directoring listing. Got: ' + DirListing.GetDebugDump());
 
diff --git a/Tests/VfsControl.pas b/Tests/VfsControl.pas
new file mode 100644
index 0000000..dd81884
--- /dev/null
+++ b/Tests/VfsControl.pas
@@ -0,0 +1,71 @@
+unit VfsControl;
+(*
+  Facade unit for high-level VFS API.
+*)
+
+
+(***)  interface  (***)
+
+uses
+  Windows, SysUtils,
+  Utils,
+  VfsBase, VfsUtils, VfsHooks;
+
+
+(* Runs all VFS subsystems, unless VFS is already running *)
+function RunVfs (DirListingOrder: VfsBase.TDirListingSortType): boolean;
+
+
+(***)  implementation  (***)
+
+
+function GetCurrentDirW: WideString;
+var
+  Buf:    array [0..32767 - 1] of WideChar;
+  ResLen: integer;
+
+begin
+  result := '';
+  ResLen := Windows.GetCurrentDirectoryW(sizeof(Buf), @Buf);
+
+  if ResLen > 0 then begin
+    SetLength(result, ResLen);
+    Utils.CopyMem(ResLen * sizeof(WideChar), @Buf, PWideChar(result));
+  end;
+end;
+
+function SetCurrentDirW (const DirPath: WideString): boolean;
+var
+  AbsPath: WideString;
+
+begin
+  AbsPath := VfsUtils.NormalizePath(DirPath);
+  result  := Windows.SetCurrentDirectoryW(PWideChar(AbsPath));
+end;
+
+function RunVfs (DirListingOrder: VfsBase.TDirListingSortType): boolean;
+var
+  CurrDir: WideString;
+
+begin
+  with VfsBase.VfsCritSection do begin
+    Enter;
+
+    result := VfsBase.RunVfs(DirListingOrder);
+    
+    if result then begin
+      VfsHooks.InstallHooks;
+
+      // Try to ensure, that current directory handle is tracked by VfsOpenFiles
+      CurrDir := GetCurrentDirW;
+
+      if CurrDir <> '' then begin
+        SetCurrentDirW(CurrDir);
+      end;
+    end;
+
+    Leave;
+  end; // .with
+end; // function RunVfs
+
+end.
\ No newline at end of file
diff --git a/Tests/VfsIntegratedTest.pas b/Tests/VfsIntegratedTest.pas
new file mode 100644
index 0000000..6622082
--- /dev/null
+++ b/Tests/VfsIntegratedTest.pas
@@ -0,0 +1,97 @@
+unit VfsIntegratedTest;
+
+(***)  interface  (***)
+
+uses
+  SysUtils, TestFramework, Windows,
+  Utils, WinUtils, ConsoleApi,
+  VfsUtils, VfsBase, VfsDebug,
+  VfsControl;
+
+type
+  TestIntegrated = class (TTestCase)
+   private
+    Inited: boolean;
+
+    function GetRootDir: string;
+
+   protected
+    procedure SetUp; override;
+    procedure TearDown; override;
+
+   published
+    procedure TestGetFileAttributes;
+  end;
+
+(***)  implementation  (***)
+
+
+procedure LogSomething (Operation, Message: pchar); stdcall;
+begin
+  WriteLn('>> ', string(Operation), ': ', string(Message), #13#10);
+end;
+
+function TestIntegrated.GetRootDir: string;
+begin
+  result := SysUtils.ExtractFileDir(WinUtils.GetExePath) + '\Tests\Fs';
+end;
+
+procedure TestIntegrated.SetUp;
+var
+  RootDir: string;
+
+begin
+  if not Inited then begin
+    Inited  := true;
+    RootDir := Self.GetRootDir;
+    VfsBase.ResetVfs();
+    VfsBase.MapDir(RootDir, RootDir + '\Mods\FullyVirtual', DONT_OVERWRITE_EXISTING);
+    VfsBase.MapDir(RootDir, RootDir + '\Mods\B', DONT_OVERWRITE_EXISTING);
+    VfsBase.MapDir(RootDir, RootDir + '\Mods\A', DONT_OVERWRITE_EXISTING);
+    VfsBase.MapDir(RootDir, RootDir + '\Mods\Apache', DONT_OVERWRITE_EXISTING);
+    VfsDebug.SetLoggingProc(LogSomething);
+    VfsControl.RunVfs(VfsBase.SORT_FIFO);
+  end;
+end;
+
+procedure TestIntegrated.TearDown;
+begin
+  VfsBase.PauseVfs();
+  VfsDebug.SetLoggingProc(nil);
+end;
+
+procedure TestIntegrated.TestGetFileAttributes;
+var
+  RootDir: string;
+
+  function HasValidAttrs (const Path: string; const RequiredAttrs: integer = 0; const ForbiddenAttrs: integer = 0): boolean;
+  var
+    Attrs: integer;
+
+  begin
+    Attrs  := Int(Windows.GetFileAttributes(pchar(Path)));
+    result := Attrs <> -1;
+
+    if result then begin
+      if RequiredAttrs <> 0 then begin
+        result := (Attrs and RequiredAttrs) = RequiredAttrs;
+      end;
+
+      if result and (ForbiddenAttrs <> 0) then begin
+        result := (Attrs and ForbiddenAttrs) = 0;
+      end;
+    end;
+  end; // .function HasValidAttrs
+
+begin
+  RootDir := Self.GetRootDir;
+  Check(not HasValidAttrs(RootDir + '\non-existing.non'), '{1}');
+  Check(HasValidAttrs(RootDir + '\Hobbots\mms.cfg', 0, Windows.FILE_ATTRIBUTE_DIRECTORY), '{2}');
+  Check(HasValidAttrs(RootDir + '\503.html', 0, Windows.FILE_ATTRIBUTE_DIRECTORY), '{3}');
+  Check(HasValidAttrs(RootDir + '\Hobbots\', Windows.FILE_ATTRIBUTE_DIRECTORY), '{4}');
+  Check(HasValidAttrs(RootDir + '\Mods', Windows.FILE_ATTRIBUTE_DIRECTORY), '{5}');
+end;
+
+begin
+  RegisterTest(TestIntegrated.Suite);
+end.
\ No newline at end of file
diff --git a/Tests/VfsTestHelper.pas b/Tests/VfsTestHelper.pas
new file mode 100644
index 0000000..624dada
--- /dev/null
+++ b/Tests/VfsTestHelper.pas
@@ -0,0 +1,46 @@
+unit VfsTestHelper;
+(*
+  
+*)
+
+
+(***)  interface  (***)
+
+uses
+  SysUtils, Windows,
+  Utils;
+
+(* Initializes debug console *)
+procedure InitConsole;
+
+
+(***)  implementation  (***)
+
+
+procedure InitConsole;
+var
+  Rect:    TSmallRect;
+  BufSize: TCoord;
+  hIn:     THandle;
+  hOut:    THandle;
+
+begin
+  AllocConsole;
+  SetConsoleCP(GetACP);
+  SetConsoleOutputCP(GetACP);
+  hIn                       := GetStdHandle(STD_INPUT_HANDLE);
+  hOut                      := GetStdHandle(STD_OUTPUT_HANDLE);
+  pinteger(@System.Input)^  := hIn;
+  pinteger(@System.Output)^ := hOut;
+  BufSize.x                 := 120;
+  BufSize.y                 := 1000;
+  SetConsoleScreenBufferSize(hOut, BufSize);
+  Rect.Left                 := 0;
+  Rect.Top                  := 0;
+  Rect.Right                := 120 - 1;
+  Rect.Bottom               := 50 - 1;
+  SetConsoleWindowInfo(hOut, true, Rect);
+  SetConsoleTextAttribute(hOut, (0 shl 4) or $0F);
+end; // .procedure InitConsole;
+
+end.
\ No newline at end of file
diff --git a/VfsBase.pas b/VfsBase.pas
index 94637e4..c8a2335 100644
--- a/VfsBase.pas
+++ b/VfsBase.pas
@@ -36,7 +36,7 @@ type
     SORT_FIFO - Items of the first mapped directory will be listed before the second mapped directory items.
     SORT_LIFO - Items of The last mapped directory will be listed before all other mapped directory items.
   *)
-  TDirListingSortType = (SORT_FIFO, SORT_LIFO);
+  TDirListingSortType = (SORT_FIFO = 0, SORT_LIFO = 1);
 
   (* Single redirected VFS entry: file or directory *)
   TVfsItem = class
@@ -79,6 +79,8 @@ type
     procedure RestoreVfsForThread;
   end;
 
+  TSingleArgExternalFunc = function (Arg: pointer = nil): integer; stdcall;
+
 var
   (* Global VFS access synchronizer *)
   VfsCritSection: Concur.TCritSection;
@@ -86,9 +88,13 @@ var
 
 function GetThreadVfsDisabler: TThreadVfsDisabler;
 
-(* Runs VFS. Higher level API must install hooks in VfsCritSection protected area *)
+(* Runs VFS. Higher level API must install hooks in VfsCritSection protected area.
+   Listing order is ignored if VFS is resumed from pause *)
 function RunVfs (DirListingOrder: TDirListingSortType): boolean;
 
+(* Temporarily pauses VFS, but does not reset existing mappings *)
+function PauseVfs: boolean;
+
 (* Stops VFS and clears all mappings *)
 function ResetVfs: boolean;
 
@@ -101,6 +107,9 @@ function GetVfsDirInfo (const AbsVirtPath, Mask: WideString; {OUT} var DirInfo:
 (* Maps real directory contents to virtual path. Target must exist for success *)
 function MapDir (const VirtPath, RealPath: WideString; OverwriteExisting: boolean; Flags: integer = 0): boolean;
 
+(* Calls specified function with a single argument and returns its result. VFS is disabled for current thread during function exection *)
+function CallWithoutVfs (Func: TSingleArgExternalFunc; Arg: pointer = nil): integer; stdcall;
+
 
 (***)  implementation  (***)
 
@@ -115,6 +124,9 @@ var
   
   (* Global VFS state indicator. If false, all VFS search operations must fail *)
   VfsIsRunning: boolean = false;
+
+  (* If true, VFS file/directory hierarchy is built and no mapping is allowed untill full reset *)
+  VfsTreeIsBuilt: boolean = false;
     
   (* Automatical VFS items priority management *)
   OverwritingPriority: integer = INITIAL_OVERWRITING_PRIORITY;
@@ -271,15 +283,32 @@ begin
       Enter;
 
       if not VfsIsRunning then begin
-        BuildVfsItemsTree();
-        SortVfsDirListings(DirListingOrder);
+        if not VfsTreeIsBuilt then begin
+          BuildVfsItemsTree();
+          SortVfsDirListings(DirListingOrder);
+          VfsTreeIsBuilt := true;
+        end;
+        
         VfsIsRunning := true;
       end;
 
+      Leave;
+    end; // .with
+  end; // .if
+end; // .function RunVfs
+
+function PauseVfs: boolean;
+begin
+  result := not DisableVfsForThisThread;
+
+  if result then begin
+    with VfsCritSection do begin
+      Enter;
+      VfsIsRunning := false;
       Leave;
     end;
   end;
-end; // .function RunVfs
+end;
 
 function ResetVfs: boolean;
 begin
@@ -288,8 +317,9 @@ begin
   if result then begin
     with VfsCritSection do begin
       Enter;
-      VfsIsRunning := false;
       VfsItems.Clear();
+      VfsIsRunning   := false;
+      VfsTreeIsBuilt := false;
       Leave;
     end;
   end;
@@ -481,9 +511,36 @@ end; // .function _MapDir
 
 function MapDir (const VirtPath, RealPath: WideString; OverwriteExisting: boolean; Flags: integer = 0): boolean;
 begin
-  result := _MapDir(NormalizePath(VirtPath), NormalizePath(RealPath), nil, OverwriteExisting, AUTO_PRIORITY) <> nil;
+  with VfsCritSection do begin
+    Enter;
+    
+    result := not VfsIsRunning and not VfsTreeIsBuilt;
+
+    if result then begin
+      result := _MapDir(NormalizePath(VirtPath), NormalizePath(RealPath), nil, OverwriteExisting, AUTO_PRIORITY) <> nil;
+    end;
+    
+    Leave;
+  end;
 end;
 
+function CallWithoutVfs (Func: TSingleArgExternalFunc; Arg: pointer = nil): integer; stdcall;
+begin
+  with GetThreadVfsDisabler do begin
+    try
+      DisableVfsForThread;
+      result := Func(Arg);
+    except
+      on E: Exception do begin
+        RestoreVfsForThread;
+        raise E;
+      end;
+    end; // .try
+
+    RestoreVfsForThread;
+  end; // .with  
+end; // .function CallWithoutVfs
+
 begin
   VfsCritSection.Init;
   VfsItems := DataLib.NewDict(Utils.OWNS_ITEMS, DataLib.CASE_SENSITIVE);
diff --git a/VfsHooks.pas b/VfsHooks.pas
new file mode 100644
index 0000000..4914629
--- /dev/null
+++ b/VfsHooks.pas
@@ -0,0 +1,556 @@
+unit VfsHooks;
+(*
+  Description: WinNT code hooks package.
+*)
+
+
+(***)  interface  (***)
+
+uses
+  Windows, SysUtils, Math,
+  Utils, WinNative, Concur,
+  StrLib, Alg,
+  VfsBase, VfsUtils, VfsPatching,
+  VfsDebug, VfsApiDigger, VfsOpenFiles;
+
+
+(* Installs VFS hooks, if not already installed, in a thread-safe manner *)
+procedure InstallHooks;
+
+
+(***)  implementation  (***)
+
+
+var
+  HooksCritSection: Concur.TCritSection;
+  HooksInstalled:   boolean = false;
+
+  NativeNtQueryAttributesFile:     WinNative.TNtQueryAttributesFile;
+  NativeNtQueryFullAttributesFile: WinNative.TNtQueryFullAttributesFile;
+  NativeNtOpenFile:                WinNative.TNtOpenFile;
+  NativeNtCreateFile:              WinNative.TNtCreateFile;
+  NativeNtClose:                   WinNative.TNtClose;
+  NativeNtQueryDirectoryFile:      WinNative.TNtQueryDirectoryFile;
+
+
+(* There is no 100% portable and reliable way to get file path by handle, unless file creation/opening
+   was tracked. Thus we rely heavily on VfsOpenFiles.
+   In Windows access to files in curren directory under relative paths is performed via [hDir, RelPath] pair,
+   thus it's strongly recommended to ensure, that current directory handle is tracked by VfsOpenedFiles.
+   It can be perfomed via SetCurrentDir(GetCurrentDir) after VFS was run *)
+function GetFilePathByHandle (hFile: THandle): WideString;
+begin
+  result := VfsOpenFiles.GetOpenedFilePath(hFile);
+end;
+
+(* Returns single absolute path, not dependant on RootDirectory member. '\??\' prefix is always removed, \\.\ and \\?\ paths remain not touched. *)
+function GetFileObjectPath (ObjectAttributes: POBJECT_ATTRIBUTES): WideString;
+var
+  FilePath: WideString;
+  DirPath:  WideString;
+
+begin
+  FilePath := ObjectAttributes.ObjectName.ToWideStr();
+  result   := '';
+
+  if FilePath <> '' then begin
+    if FilePath[1] = '\' then begin
+      FilePath := VfsUtils.StripNtAbsPathPrefix(FilePath);
+    end;
+
+    if ObjectAttributes.RootDirectory <> 0 then begin
+      DirPath := GetFilePathByHandle(ObjectAttributes.RootDirectory);
+
+      if DirPath <> '' then begin
+        if DirPath[Length(DirPath)] <> '\' then begin
+          result := DirPath + '\' + FilePath;
+        end else begin
+          result := DirPath + FilePath;
+        end;        
+      end;
+    end else begin
+      result := FilePath;
+    end;
+  end; // .if
+end; // .function GetFileObjectPath
+
+function Hook_NtQueryAttributesFile (OrigFunc: WinNative.TNtQueryAttributesFile; ObjectAttributes: POBJECT_ATTRIBUTES; FileInformation: PFILE_BASIC_INFORMATION): NTSTATUS; stdcall;
+var
+  ExpandedPath:     WideString;
+  RedirectedPath:   WideString;
+  ReplacedObjAttrs: WinNative.TObjectAttributes;
+  FileInfo:         TNativeFileInfo;
+  HadTrailingDelim: boolean;
+
+begin
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtQueryAttributesFile', Format('Dir: %d. Path: "%s"', [ObjectAttributes.RootDirectory, ObjectAttributes.ObjectName.ToWideStr()]));
+  end;
+
+  ReplacedObjAttrs        := ObjectAttributes^;
+  ReplacedObjAttrs.Length := sizeof(ReplacedObjAttrs);
+  ExpandedPath            := GetFileObjectPath(ObjectAttributes);
+  RedirectedPath          := '';
+
+  if ExpandedPath <> '' then begin
+    RedirectedPath := VfsBase.GetVfsItemRealPath(StrLib.ExcludeTrailingDelimW(ExpandedPath, @HadTrailingDelim), @FileInfo);
+  end;
+
+  // Return cached VFS file info
+  if RedirectedPath <> '' then begin
+    if not HadTrailingDelim or Utils.HasFlag(FILE_ATTRIBUTE_DIRECTORY, FileInfo.Base.FileAttributes) then begin
+      FileInformation.CreationTime   := FileInfo.Base.CreationTime;
+      FileInformation.LastAccessTime := FileInfo.Base.LastAccessTime;
+      FileInformation.LastWriteTime  := FileInfo.Base.LastWriteTime;
+      FileInformation.ChangeTime     := FileInfo.Base.ChangeTime;
+      FileInformation.FileAttributes := FileInfo.Base.FileAttributes;
+      result                         := WinNative.STATUS_SUCCESS;
+    end else begin
+      result := WinNative.STATUS_NO_SUCH_FILE;
+    end;
+  end
+  // Query file with real path
+  else begin
+    RedirectedPath := ExpandedPath;
+
+    if RedirectedPath <> '' then begin
+      if RedirectedPath[1] <> '\' then begin
+        RedirectedPath := '\??\' + RedirectedPath;
+      end;
+
+      ReplacedObjAttrs.RootDirectory := 0;
+      ReplacedObjAttrs.Attributes    := ReplacedObjAttrs.Attributes or WinNative.OBJ_CASE_INSENSITIVE;
+      ReplacedObjAttrs.ObjectName.AssignExistingStr(RedirectedPath);
+    end;
+    
+    result := OrigFunc(@ReplacedObjAttrs, FileInformation);
+  end; // .else
+
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtQueryAttributesFile', Format('Result: %x. Attrs: 0x%x. Path: "%s" => "%s"', [result, FileInformation.FileAttributes, string(ExpandedPath), string(RedirectedPath)]));
+  end;
+end; // .function Hook_NtQueryAttributesFile
+
+function Hook_NtQueryFullAttributesFile (OrigFunc: WinNative.TNtQueryFullAttributesFile; ObjectAttributes: POBJECT_ATTRIBUTES; FileInformation: PFILE_NETWORK_OPEN_INFORMATION): NTSTATUS; stdcall;
+var
+  ExpandedPath:     WideString;
+  RedirectedPath:   WideString;
+  ReplacedObjAttrs: WinNative.TObjectAttributes;
+  HadTrailingDelim: boolean;
+
+begin
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtQueryFullAttributesFile', Format('Dir: %d. Path: "%s"', [ObjectAttributes.RootDirectory, ObjectAttributes.ObjectName.ToWideStr()]));
+  end;
+
+  ReplacedObjAttrs        := ObjectAttributes^;
+  ReplacedObjAttrs.Length := sizeof(ReplacedObjAttrs);
+  ExpandedPath            := GetFileObjectPath(ObjectAttributes);
+  RedirectedPath          := '';
+
+  if ExpandedPath <> '' then begin
+    RedirectedPath := VfsBase.GetVfsItemRealPath(StrLib.ExcludeTrailingDelimW(ExpandedPath, @HadTrailingDelim));
+  end;
+
+  if RedirectedPath = '' then begin
+    RedirectedPath := ExpandedPath;
+  end else if HadTrailingDelim then begin
+    RedirectedPath := RedirectedPath + '\';
+  end;
+    
+  if (RedirectedPath <> '') and (RedirectedPath[1] <> '\') then begin
+    RedirectedPath := '\??\' + RedirectedPath;
+  end;
+
+  ReplacedObjAttrs.RootDirectory := 0;
+  ReplacedObjAttrs.Attributes    := ReplacedObjAttrs.Attributes or WinNative.OBJ_CASE_INSENSITIVE;
+  ReplacedObjAttrs.ObjectName.AssignExistingStr(RedirectedPath);
+  
+  result := OrigFunc(@ReplacedObjAttrs, FileInformation);
+
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtQueryFullAttributesFile', Format('Result: %x. Attrs: 0x%x. Path: "%s" => "%s"', [result, FileInformation.FileAttributes, string(ExpandedPath), string(RedirectedPath)]));
+  end;
+end; // .Hook_NtQueryFullAttributesFile
+
+function Hook_NtOpenFile (OrigFunc: WinNative.TNtOpenFile; FileHandle: PHANDLE; DesiredAccess: ACCESS_MASK; ObjectAttributes: POBJECT_ATTRIBUTES;
+                          IoStatusBlock: PIO_STATUS_BLOCK; ShareAccess: ULONG; OpenOptions: ULONG): NTSTATUS; stdcall;
+begin
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtOpenFile', ObjectAttributes.ObjectName.ToWideStr());
+  end;
+
+  result := WinNative.NtCreateFile(FileHandle, DesiredAccess, ObjectAttributes, IoStatusBlock, nil, 0, ShareAccess, WinNative.FILE_OPEN, OpenOptions, nil, 0);
+end;
+
+function Hook_NtCreateFile (OrigFunc: WinNative.TNtCreateFile; FileHandle: PHANDLE; DesiredAccess: ACCESS_MASK; ObjectAttributes: POBJECT_ATTRIBUTES; IoStatusBlock: PIO_STATUS_BLOCK;
+                            AllocationSize: PLARGE_INTEGER; FileAttributes: ULONG; ShareAccess: ULONG; CreateDisposition: ULONG; CreateOptions: ULONG; EaBuffer: PVOID; EaLength: ULONG): NTSTATUS; stdcall;
+var
+  ExpandedPath:     WideString;
+  RedirectedPath:   WideString;
+  ReplacedObjAttrs: WinNative.TObjectAttributes;
+  HadTrailingDelim: boolean;
+
+  FileInfo: Windows.TWin32FindDataW;
+
+begin
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtCreateFile', ObjectAttributes.ObjectName.ToWideStr());
+  end;
+
+  ReplacedObjAttrs        := ObjectAttributes^;
+  ReplacedObjAttrs.Length := sizeof(ReplacedObjAttrs);
+  ExpandedPath            := GetFileObjectPath(ObjectAttributes);
+  RedirectedPath          := '';
+
+  if (ExpandedPath <> '') and ((DesiredAccess and WinNative.DELETE) = 0) and (CreateDisposition = WinNative.FILE_OPEN) then begin
+    RedirectedPath := VfsBase.GetVfsItemRealPath(StrLib.ExcludeTrailingDelimW(ExpandedPath, @HadTrailingDelim), @FileInfo);
+  end;
+
+  if RedirectedPath = '' then begin
+    RedirectedPath := ExpandedPath;
+  end else if HadTrailingDelim then begin
+    RedirectedPath := RedirectedPath + '\';
+  end;
+
+  if (RedirectedPath <> '') and (RedirectedPath[1] <> '\') then begin
+    RedirectedPath := '\??\' + RedirectedPath;
+  end;
+
+  ReplacedObjAttrs.RootDirectory := 0;
+  ReplacedObjAttrs.Attributes    := ReplacedObjAttrs.Attributes or WinNative.OBJ_CASE_INSENSITIVE;
+  ReplacedObjAttrs.ObjectName.AssignExistingStr(RedirectedPath);
+
+  result := OrigFunc(FileHandle, DesiredAccess, @ReplacedObjAttrs, IoStatusBlock, AllocationSize, FileAttributes, ShareAccess, CreateDisposition, CreateOptions, EaBuffer, EaLength);
+
+  if (result = WinNative.STATUS_SUCCESS) and Utils.HasFlag(WinNative.FILE_SYNCHRONOUS_IO_NONALERT, CreateOptions) and Utils.HasFlag(WinNative.SYNCHRONIZE, DesiredAccess) then begin
+    VfsOpenFiles.SetOpenedFileInfo(FileHandle^, TOpenedFile.Create(FileHandle^, ExpandedPath));
+  end;
+
+  if VfsDebug.LoggingEnabled then begin
+    if ExpandedPath <> StripNtAbsPathPrefix(RedirectedPath) then begin
+      WriteLog('NtCreateFile', Format('Access: 0x%x. Handle: %x. Status: %x. Redirected "%s" => "%s"', [DesiredAccess, FileHandle^, result, StrLib.WideToAnsiSubstitute(ExpandedPath), StrLib.WideToAnsiSubstitute(StripNtAbsPathPrefix(RedirectedPath))]));
+    end else begin
+      WriteLog('NtCreateFile', Format('Access: 0x%x. Handle: %x. Status: %x. Path: "%s"', [DesiredAccess, FileHandle^, result, StrLib.WideToAnsiSubstitute(ExpandedPath)]));
+    end;
+  end;
+end; // .function Hook_NtCreateFile
+
+function Hook_NtClose (OrigFunc: WinNative.TNtClose; hData: HANDLE): NTSTATUS; stdcall;
+begin
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtClose', Format('Handle: %x', [integer(hData)]));
+  end;
+
+  with OpenFilesCritSection do begin
+    Enter;
+    result := OrigFunc(hData);
+
+    if WinNative.NT_SUCCESS(result) then begin
+      VfsOpenFiles.DeleteOpenedFileInfo(hData);
+    end;
+
+    Leave;
+  end;
+  
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtClose', Format('Status: %x', [integer(result)]));
+  end;
+end; // .function Hook_NtClose
+
+function IsSupportedFileInformationClass (FileInformationClass: integer): boolean;
+begin
+  result := (FileInformationClass <= High(byte)) and (FILE_INFORMATION_CLASS(byte(FileInformationClass)) in [FileBothDirectoryInformation, FileDirectoryInformation, FileFullDirectoryInformation, FileIdBothDirectoryInformation, FileIdFullDirectoryInformation, FileNamesInformation]);
+end;
+
+type
+  TFileInfoConvertResult  = (TOO_SMALL_BUF, COPIED_ALL, TRUNCATED_NAME);
+  TTruncatedNamesStrategy = (DONT_TRUNCATE_NAMES, TRUNCATE_NAMES);
+
+function ConvertFileInfoStruct (SrcInfo: PNativeFileInfo; TargetFormat: FILE_INFORMATION_CLASS; {n} Buf: pointer; BufSize: integer; TruncatedNamesStrategy: TTruncatedNamesStrategy;
+                                {OUT} var BytesWritten: integer): TFileInfoConvertResult;
+var
+{n} FileNameBuf:     pointer;
+    FileNameBufSize: integer;
+    StructBaseSize:  integer;
+    StructFullSize:  integer;
+
+begin
+  {!} Assert(SrcInfo <> nil);
+  {!} Assert(IsSupportedFileInformationClass(ord(TargetFormat)), Format('Unsupported file information class: %d', [ord(TargetFormat)]));
+  FileNameBuf := nil;
+  // * * * * * //
+  BytesWritten   := 0;
+  StructBaseSize := WinNative.GetFileInformationClassSize(TargetFormat);
+  StructFullSize := StructBaseSize + Int(SrcInfo.Base.FileNameLength);
+
+  if (Buf = nil) or (BufSize < StructBaseSize)  then begin
+    result := TOO_SMALL_BUF;
+    exit;
+  end;
+
+  result := COPIED_ALL;
+
+  if BufSize < StructFullSize then begin
+    result := TRUNCATED_NAME;
+
+    if TruncatedNamesStrategy = DONT_TRUNCATE_NAMES then begin
+      exit;
+    end;
+  end;
+
+  case TargetFormat of
+    FileNamesInformation: PFILE_NAMES_INFORMATION(Buf).FileNameLength := SrcInfo.Base.FileNameLength;
+   
+    FileBothDirectoryInformation, FileDirectoryInformation, FileFullDirectoryInformation, FileIdBothDirectoryInformation, FileIdFullDirectoryInformation: begin
+      Utils.CopyMem(StructBaseSize, @SrcInfo.Base, Buf);
+    end;
+  else
+    {!} Assert(IsSupportedFileInformationClass(ord(TargetFormat)), Format('Unexpected unsupported file information class: %d', [ord(TargetFormat)]));
+  end;
+
+  FileNameBufSize := Min(BufSize - StructBaseSize, SrcInfo.Base.FileNameLength) and not $00000001;
+  FileNameBuf     := Utils.PtrOfs(Buf, StructBaseSize);
+
+  Utils.CopyMem(FileNameBufSize, PWideChar(SrcInfo.FileName), FileNameBuf);
+
+  BytesWritten := StructBaseSize + FileNameBufSize;
+end; // .function ConvertFileInfoStruct
+
+function Hook_NtQueryDirectoryFile (OrigFunc: WinNative.TNtQueryDirectoryFile; FileHandle: HANDLE; Event: HANDLE; ApcRoutine: pointer; ApcContext: PVOID; Io: PIO_STATUS_BLOCK; Buffer: PVOID;
+                                    BufLength: ULONG; InfoClass: integer (* FILE_INFORMATION_CLASS *); SingleEntry: BOOLEAN; {n} Mask: PUNICODE_STRING; RestartScan: BOOLEAN): NTSTATUS; stdcall;
+const
+  ENTRIES_ALIGNMENT = 8;
+
+type
+  PPrevEntry = ^TPrevEntry;
+  TPrevEntry = packed record
+    NextEntryOffset: ULONG;
+    FileIndex:       ULONG;
+  end;
+
+var
+{Un} OpenedFile:             TOpenedFile;
+{Un} FileInfo:               TFileInfo;
+{n}  BufCurret:              pointer;
+{n}  PrevEntry:              PPrevEntry;
+     BufSize:                integer;
+     BufSizeLeft:            integer;
+     BytesWritten:           integer;
+     IsFirstEntry:           boolean;
+     Proceed:                boolean;
+     TruncatedNamesStrategy: TTruncatedNamesStrategy;
+     StructConvertResult:    TFileInfoConvertResult;
+     EmptyMask:              UNICODE_STRING;
+     EntryName:              WideString;
+
+begin
+  OpenedFile := nil;
+  FileInfo   := nil;
+  BufCurret  := nil;
+  PrevEntry  := nil;
+  BufSize    := 0;
+  // * * * * * //
+  with OpenFilesCritSection do begin
+    if Mask = nil then begin
+      EmptyMask.Reset;
+      Mask := @EmptyMask;
+    end;
+
+    if VfsDebug.LoggingEnabled then begin
+      WriteLog('NtQueryDirectoryFile', Format('Handle: %x. InfoClass: %s. Mask: %s', [integer(FileHandle), WinNative.FileInformationClassToStr(InfoClass), AnsiString(Mask.ToWideStr())]));
+    end;
+
+    Enter;
+
+    // FIXME REWRITE ME
+    //OpenedFile := OpenedFiles[pointer(FileHandle)];
+
+    if (OpenedFile = nil) or (Event <> 0) or (ApcRoutine <> nil) or (ApcContext <> nil) then begin
+      WriteLog('NtQueryDirectoryFile', Format('Calling native NtQueryDirectoryFile. OpenedFile: %x. %d %d %d', [integer(OpenedFile), integer(Event), integer(ApcRoutine), integer(ApcContext)]));
+      result := OrigFunc(FileHandle, Event, ApcRoutine, ApcContext, Io, Buffer, BufLength, InfoClass, SingleEntry, Mask, RestartScan);
+    end else begin
+      int(Io.Information) := 0;
+      result              := STATUS_SUCCESS;
+
+      if RestartScan then begin
+        SysUtils.FreeAndNil(OpenedFile.DirListing);
+      end;
+
+      OpenedFile.FillDirListing(Mask.ToWideStr());
+
+      Proceed := (Buffer <> nil) and (BufLength > 0);
+
+      // Validate buffer
+      if not Proceed then begin
+        result := STATUS_INVALID_BUFFER_SIZE;
+      end else begin
+        BufSize := Utils.IfThen(int(BufLength) > 0, int(BufLength), High(int));
+      end;
+
+      // Validate information class
+      if Proceed then begin
+        Proceed := IsSupportedFileInformationClass(InfoClass);
+
+        if not Proceed then begin
+          result := STATUS_INVALID_INFO_CLASS;
+        end;
+      end;
+
+      // Signal of scanning end, if necessary
+      if Proceed then begin
+        Proceed := not OpenedFile.DirListing.IsEnd;
+
+        if not Proceed then begin
+          result := STATUS_NO_MORE_FILES;
+        end;
+      end;
+
+      // Scan directory
+      if Proceed then begin
+        BufCurret    := Buffer;
+        BytesWritten := 1;
+
+        while (BytesWritten > 0) and OpenedFile.DirListing.GetNextItem(FileInfo) do begin
+          // Align next record to 8-bytes boundary from Buffer start
+          BufCurret   := pointer(int(Buffer) + Alg.IntRoundToBoundary(int(Io.Information), ENTRIES_ALIGNMENT));
+          BufSizeLeft := BufSize - (int(BufCurret) - int(Buffer));
+
+          IsFirstEntry := OpenedFile.DirListing.FileInd = 1;
+
+          if IsFirstEntry then begin
+            TruncatedNamesStrategy := TRUNCATE_NAMES;
+          end else begin
+            TruncatedNamesStrategy := DONT_TRUNCATE_NAMES;
+          end;
+
+          StructConvertResult := ConvertFileInfoStruct(@FileInfo.Data, FILE_INFORMATION_CLASS(byte(InfoClass)), BufCurret, BufSizeLeft, TruncatedNamesStrategy, BytesWritten);
+
+          if VfsDebug.LoggingEnabled then begin
+            EntryName := Copy(FileInfo.Data.FileName, 1, Min(BytesWritten - WinNative.GetFileInformationClassSize(InfoClass), FileInfo.Data.Base.FileNameLength) div 2);
+            WriteLog('NtQueryDirectoryFile', 'Written entry: ' + EntryName);
+          end;
+
+          //VarDump(['Converted struct to buf offset:', int(BufCurret) - int(Buffer), 'Written:', BytesWritten, 'Result:', ord(StructConvertResult)]);
+
+          with PFILE_ID_BOTH_DIR_INFORMATION(BufCurret)^ do begin
+            NextEntryOffset := 0;
+            FileIndex       := 0;
+          end;
+
+          if StructConvertResult = TOO_SMALL_BUF then begin
+            OpenedFile.DirListing.SeekRel(-1);
+
+            if IsFirstEntry then begin
+              result := STATUS_BUFFER_TOO_SMALL;
+            end;
+          end else if StructConvertResult = TRUNCATED_NAME then begin
+            if IsFirstEntry then begin
+              result := STATUS_BUFFER_OVERFLOW;
+              Inc(int(Io.Information), BytesWritten);
+            end else begin
+              OpenedFile.DirListing.SeekRel(-1);
+            end;
+          end else if StructConvertResult = COPIED_ALL then begin
+            if PrevEntry <> nil then begin
+              int(Io.Information) := int(BufCurret) - int(Buffer) + BytesWritten;
+            end else begin
+              int(Io.Information) := BytesWritten;
+            end;
+          end; // .else
+
+          if (BytesWritten > 0) and (PrevEntry <> nil) then begin
+            PrevEntry.NextEntryOffset := cardinal(int(BufCurret) - int(PrevEntry));
+          end;
+
+          PrevEntry := BufCurret;
+
+          //Msg(Format('Written: %d. Total: %d', [BytesWritten, int(Io.Information)]));
+
+          if SingleEntry then begin
+            BytesWritten := 0;
+          end;
+        end; // .while
+      end; // .if    
+
+      Io.Status.Status := result;
+    end; // .else
+
+    Leave;
+  end; // .with
+
+  if VfsDebug.LoggingEnabled then begin
+    WriteLog('NtQueryDirectoryFile', Format('Status: %x. Written: %d bytes', [integer(result), integer(Io.Information)]));
+  end;
+end; // .function Hook_NtQueryDirectoryFile
+
+procedure InstallHooks;
+var
+  hDll:        Windows.THandle;
+  NtdllHandle: integer;
+
+begin
+  with HooksCritSection do begin
+    Enter;
+
+    if not HooksInstalled then begin
+      HooksInstalled := true;
+
+      // Ensure, that library with VFS hooks installed is never unloaded
+      if System.IsLibrary then begin
+        WinNative.GetModuleHandleExW(WinNative.GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS or WinNative.GET_MODULE_HANDLE_EX_FLAG_PIN, @InstallHooks, hDll);
+      end;
+
+      NtdllHandle:= Windows.GetModuleHandle('ntdll.dll');
+      {!} Assert(NtdllHandle <> 0, 'Failed to load ntdll.dll library');
+
+      WriteLog('InstallHook', 'Installing NtQueryAttributesFile hook');
+      NativeNtQueryAttributesFile := VfsPatching.SpliceWinApi
+      (
+        VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtQueryAttributesFile'),
+        @Hook_NtQueryAttributesFile
+      );
+
+      // WriteLog('InstallHook', 'Installing NtQueryFullAttributesFile hook');
+      // NativeNtQueryFullAttributesFile := VfsPatching.SpliceWinApi
+      // (
+      //   VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtQueryFullAttributesFile'),
+      //   @Hook_NtQueryFullAttributesFile
+      // );
+
+      // WriteLog('InstallHook', 'Installing NtOpenFile hook');
+      // NativeNtOpenFile := VfsPatching.SpliceWinApi
+      // (
+      //   VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtOpenFile'),
+      //   @Hook_NtOpenFile
+      // );
+
+      // WriteLog('InstallHook', 'Installing NtCreateFile hook');
+      // NativeNtCreateFile := VfsPatching.SpliceWinApi
+      // (
+      //   VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtCreateFile'),
+      //   @Hook_NtCreateFile
+      // );
+
+      // WriteLog('InstallHook', 'Installing NtClose hook');
+      // NativeNtClose := VfsPatching.SpliceWinApi
+      // (
+      //   VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtClose'),
+      //   @Hook_NtClose
+      // );
+
+      // WriteLog('InstallHook', 'Installing NtQueryDirectoryFile hook');
+      // NativeNtQueryDirectoryFile := VfsPatching.SpliceWinApi
+      // (
+      //   VfsApiDigger.GetRealProcAddress(NtdllHandle, 'NtQueryDirectoryFile'),
+      //   @Hook_NtQueryDirectoryFile
+      // );
+    end; // .if
+
+    Leave;
+  end; // .with
+end; // .procedure InstallHooks
+
+begin
+  HooksCritSection.Init;
+end.
\ No newline at end of file
diff --git a/VfsPatching.pas b/VfsPatching.pas
new file mode 100644
index 0000000..1385180
--- /dev/null
+++ b/VfsPatching.pas
@@ -0,0 +1,129 @@
+unit VfsPatching;
+(*
+  Description: Code patching facilities, based on PatchForge library.
+               All hooks are thread-safe.
+*)
+
+
+(***)  interface  (***)
+
+uses
+  Windows, SysUtils, Utils, PatchForge;
+
+
+(* Replaces original STDCALL function with the new one with the same prototype and one extra argument.
+   The argument is callable pointer, used to execute original function. The pointer is passed as THE FIRST
+   argument before other arguments. *)
+function SpliceWinApi (OrigFunc, HandlerFunc: pointer): pointer;
+
+
+(***)  implementation  (***)
+
+
+type
+  (* Import *)
+  TPatchMaker  = PatchForge.TPatchMaker;
+  TPatchHelper = PatchForge.TPatchHelper;
+
+
+(* Writes arbitrary data to any write-protected section *)
+function WriteAtCode (NumBytes: integer; {n} Src, {n} Dst: pointer): boolean;
+var
+  OldPageProtect: integer;
+
+begin
+  {!} Assert(Utils.IsValidBuf(Src, NumBytes));
+  {!} Assert(Utils.IsValidBuf(Dst, NumBytes));
+  result := NumBytes = 0;
+
+  if not result then begin
+    try
+      result := Windows.VirtualProtect(Dst, NumBytes, Windows.PAGE_EXECUTE_READWRITE, @OldPageProtect);
+      
+      if result then begin
+        Utils.CopyMem(NumBytes, Src, Dst);
+        Windows.VirtualProtect(Dst, NumBytes, OldPageProtect, @OldPageProtect);
+      end;
+    except
+      result := false;
+    end;
+  end; // .if
+end; // .function WriteAtCode
+
+(* Writes patch to any write-protected section *)
+function WritePatchAtCode (PatchMaker: TPatchMaker; {n} Dst: pointer): boolean;
+var
+  Buf: Utils.TArrayOfByte;
+
+begin
+  {!} Assert(PatchMaker <> nil);
+  {!} Assert((Dst <> nil) or (PatchMaker.Size = 0));
+  // * * * * * //
+  result := true;
+
+  if PatchMaker.Size > 0 then begin
+    SetLength(Buf, PatchMaker.Size);
+    PatchMaker.ApplyPatch(pointer(Buf), Dst);
+    result := WriteAtCode(Length(Buf), pointer(Buf), Dst);
+  end;
+end; // .function WritePatchAtCode
+
+function SpliceWinApi (OrigFunc, HandlerFunc: pointer): pointer;
+const
+  CODE_ADDR_ALIGNMENT = 8;
+
+var
+{O}  p:                      PatchForge.TPatchHelper;
+{OI} SpliceBridge:           pbyte; // Memory is never freed        
+     OrigFuncBridgeLabel:    string;
+     OrigCodeBridgeStartPos: integer;
+     OverwrittenCodeSize:    integer;
+
+begin
+  {!} Assert(OrigFunc <> nil);
+  {!} Assert(HandlerFunc <> nil);
+  p            := TPatchHelper.Wrap(TPatchMaker.Create);
+  SpliceBridge := nil;
+  result       := nil;
+  // * * * * * //
+
+  // === BEGIN generating SpliceBridge ===
+  // Add pointer to original function bridge as the first argument
+  p.WriteTribyte(PatchForge.INSTR_PUSH_PTR_ESP);
+  p.WriteInt(PatchForge.INSTR_MOV_ESP_PLUS_4_CONST32);
+  p.ExecActionOnApply(PatchForge.TAddLabelRealAddrAction.Create(p.NewAutoLabel(OrigFuncBridgeLabel)));
+  p.WriteInt(0);
+
+  // Jump to new handler
+  p.Jump(PatchForge.JMP, HandlerFunc);
+  
+  // Ensure original code bridge is aligned
+  p.Nop(p.Pos mod CODE_ADDR_ALIGNMENT);
+
+  // Set result to offset from splice bridge start to original function bridge
+  result := pointer(p.Pos);
+  
+  // Write original function bridge
+  p.PutLabel(OrigFuncBridgeLabel);
+  OrigCodeBridgeStartPos := p.Pos;
+  p.WriteCode(OrigFunc, PatchForge.TMinCodeSizeDetector.Create(sizeof(PatchForge.TJumpCall32Rec)));
+  OverwrittenCodeSize := p.Pos - OrigCodeBridgeStartPos;
+  p.Jump(PatchForge.JMP, Utils.PtrOfs(OrigFunc, OverwrittenCodeSize));
+  // === END generating SpliceBridge ===
+
+  // Persist splice bridge
+  GetMem(SpliceBridge, p.Size);
+  WritePatchAtCode(p.PatchMaker, SpliceBridge);
+
+  // Turn result from offset to absolute address
+  result := Ptr(integer(SpliceBridge) + integer(result));
+
+  // Create and apply hook at target function start
+  p.Clear();
+  p.Jump(PatchForge.JMP, SpliceBridge);
+  WritePatchAtCode(p.PatchMaker, OrigFunc);
+  // * * * * * //
+  p.Release;
+end;
+
+end.
\ No newline at end of file
diff --git a/VfsTest.dpr b/VfsTest.dpr
index 702b9eb..f5feb2c 100644
--- a/VfsTest.dpr
+++ b/VfsTest.dpr
@@ -4,10 +4,13 @@ uses
   TestFramework, GuiTestRunner,
   VfsUtils, VfsBase, VfsDebug,
   VfsApiDigger, VfsExport, VfsOpenFiles,
+  VfsHooks, VfsControl,
+  VfsTestHelper,
   VfsDebugTest, VfsUtilsTest, VfsBaseTest,
-  VfsApiDiggerTest, VfsOpenFilesTest;
+  VfsApiDiggerTest, VfsOpenFilesTest, VfsIntegratedTest;
 
 begin
+  VfsTestHelper.InitConsole;
   TGUITestRunner.RunRegisteredTests;
 end.
 
diff --git a/_TODO_.txt b/_TODO_.txt
new file mode 100644
index 0000000..ebb4d42
--- /dev/null
+++ b/_TODO_.txt
@@ -0,0 +1,15 @@
+UTF-8 Logging
+
+SetCurrentDirectoryW(GetCurrentDirectoryW)
+System.IsMultiThread for DLL and exported API
+
+(* Trying to turn off DEP *)
+SetProcessDEPPolicyAddr := Windows.GetProcAddress(Kernel32Handle, 'SetProcessDEPPolicy');
+
+if SetProcessDEPPolicyAddr <> nil then begin
+  if PatchApi.Call(PatchApi.STDCALL_, SetProcessDEPPolicyAddr, [0]) <> 0 then begin
+    Log.Write('VFS', 'SetProcessDEPPolicy', 'DEP was turned off');
+  end else begin
+    Log.Write('VFS', 'SetProcessDEPPolicy', 'Failed to turn DEP off');
+  end;
+end;
\ No newline at end of file