diff --git a/README.markdown b/README.markdown
index 19b841b..48d216b 100644
--- a/README.markdown
+++ b/README.markdown
@@ -59,7 +59,7 @@ Installation
 
     git clone https://github.com/scrooloose/nerdtree.git ~/.vim/bundle/nerdtree
 
-Then reload vim, run `:helptags ~/.vim/bundle/nerdtree/doc/`, and check out `:help NERD_tree.txt`.
+Then reload Vim, run `:helptags ~/.vim/bundle/nerdtree/doc/`, and check out `:help NERDTree.txt`.
 
 
 #### [apt-vim](https://github.com/egalpin/apt-vim)
diff --git a/doc/NERD_tree.txt b/doc/NERDTree.txt
similarity index 99%
rename from doc/NERD_tree.txt
rename to doc/NERDTree.txt
index 427e90c..f68880c 100644
--- a/doc/NERD_tree.txt
+++ b/doc/NERDTree.txt
@@ -1,4 +1,4 @@
-*NERD_tree.txt*   A tree explorer plugin that owns your momma!
+*NERDTree.txt*   A tree explorer plugin that owns your momma!
 
 
 
diff --git a/lib/nerdtree/tree_dir_node.vim b/lib/nerdtree/tree_dir_node.vim
index 61f72e4..5ca94d4 100644
--- a/lib/nerdtree/tree_dir_node.vim
+++ b/lib/nerdtree/tree_dir_node.vim
@@ -45,9 +45,14 @@ function! s:TreeDirNode.addChild(treenode, inOrder)
 endfunction
 
 " FUNCTION: TreeDirNode.close() {{{1
-" Closes this directory
+" Mark this TreeDirNode as closed.
 function! s:TreeDirNode.close()
-    let self.isOpen = 0
+
+    " Close all directories in this directory node's cascade. This is
+    " necessary to ensure consistency when cascades are rendered.
+    for l:dirNode in self.getCascade()
+        let l:dirNode.isOpen = 0
+    endfor
 endfunction
 
 " FUNCTION: TreeDirNode.closeChildren() {{{1
@@ -78,19 +83,29 @@ function! s:TreeDirNode.createChild(path, inOrder)
 endfunction
 
 " FUNCTION: TreeDirNode.displayString() {{{1
-unlet s:TreeDirNode.displayString
+" Assemble and return a string that can represent this TreeDirNode object in
+" the NERDTree window.
 function! s:TreeDirNode.displayString()
-    let cascade = self.getCascade()
-    let rv = ""
-    for node in cascade
-        let rv = rv . node.path.displayString()
+    let l:result = ''
+
+    " Build a label that identifies this TreeDirNode.
+    let l:label = ''
+    let l:cascade = self.getCascade()
+    for l:dirNode in l:cascade
+        let l:label .= l:dirNode.path.displayString()
     endfor
 
-    let sym = cascade[-1].isOpen ? g:NERDTreeDirArrowCollapsible : g:NERDTreeDirArrowExpandable
+    " Select the appropriate open/closed status indicator symbol.
+    if l:cascade[-1].isOpen
+        let l:symbol = g:NERDTreeDirArrowCollapsible
+    else
+        let l:symbol = g:NERDTreeDirArrowExpandable
+    endif
 
-    let flags = cascade[-1].path.flagSet.renderToString()
+    let l:flags = l:cascade[-1].path.flagSet.renderToString()
 
-    return sym . ' ' . flags . rv
+    let l:result = l:symbol . ' ' . l:flags . l:label
+    return l:result
 endfunction
 
 " FUNCTION: TreeDirNode.findNode(path) {{{1
@@ -400,25 +415,39 @@ function! s:TreeDirNode.New(path, nerdtree)
     return newTreeNode
 endfunction
 
-" FUNCTION: TreeDirNode.open([opts]) {{{1
-" Open the dir in the current tree or in a new tree elsewhere.
-"
-" If opening in the current tree, return the number of cached nodes.
-unlet s:TreeDirNode.open
+" FUNCTION: TreeDirNode.open([options]) {{{1
+" Open this directory node in the current tree or elsewhere if special options
+" are provided. Return 0 if options were processed. Otherwise, return the
+" number of new cached nodes.
 function! s:TreeDirNode.open(...)
-    let opts = a:0 ? a:1 : {}
+    let l:options = a:0 ? a:1 : {}
 
-    if has_key(opts, 'where') && !empty(opts['where'])
-        let opener = g:NERDTreeOpener.New(self.path, opts)
-        call opener.open(self)
-    else
-        let self.isOpen = 1
-        if self.children ==# []
-            return self._initChildren(0)
-        else
-            return 0
-        endif
+    " If special options were specified, process them and return.
+    if has_key(l:options, 'where') && !empty(l:options['where'])
+        let l:opener = g:NERDTreeOpener.New(self.path, l:options)
+        call l:opener.open(self)
+        return 0
     endif
+
+    " Open any ancestors of this node that render within the same cascade.
+    let l:parent = self.parent
+    while !empty(l:parent) && !l:parent.isRoot()
+        if index(l:parent.getCascade(), self) >= 0
+            let l:parent.isOpen = 1
+            let l:parent = l:parent.parent
+        else
+            break
+        endif
+    endwhile
+
+    let self.isOpen = 1
+
+    let l:numChildrenCached = 0
+    if empty(self.children)
+        let l:numChildrenCached = self._initChildren(0)
+    endif
+
+    return l:numChildrenCached
 endfunction
 
 " FUNCTION: TreeDirNode.openAlong([opts]) {{{1
@@ -463,35 +492,16 @@ function! s:TreeDirNode._openInNewTab()
 endfunction
 
 " FUNCTION: TreeDirNode.openRecursively() {{{1
-" Opens this treenode and all of its children whose paths arent 'ignored'
-" because of the file filters.
-"
-" This method is actually a wrapper for the OpenRecursively2 method which does
-" the work.
+" Open this directory node and any descendant directory nodes whose pathnames
+" are not ignored.
 function! s:TreeDirNode.openRecursively()
-    call self._openRecursively2(1)
-endfunction
+    silent call self.open()
 
-" FUNCTION: TreeDirNode._openRecursively2() {{{1
-" Opens this all children of this treenode recursively if either:
-"   *they arent filtered by file filters
-"   *a:forceOpen is 1
-"
-" Args:
-" forceOpen: 1 if this node should be opened regardless of file filters
-function! s:TreeDirNode._openRecursively2(forceOpen)
-    if self.path.ignore(self.getNerdtree()) ==# 0 || a:forceOpen
-        let self.isOpen = 1
-        if self.children ==# []
-            call self._initChildren(1)
+    for l:child in self.children
+        if l:child.path.isDirectory && !l:child.path.ignore(l:child.getNerdtree())
+            call l:child.openRecursively()
         endif
-
-        for i in self.children
-            if i.path.isDirectory ==# 1
-                call i._openRecursively2(0)
-            endif
-        endfor
-    endif
+    endfor
 endfunction
 
 " FUNCTION: TreeDirNode.refresh() {{{1