diff --git a/next.py b/next.py
index 837ad62..6450ed6 100644
--- a/next.py
+++ b/next.py
@@ -236,8 +236,13 @@ class TangleFileTreeElement(TangleBlob):
             self.inodes[atom.name] = atom
 
     def _applyAtom(self, atom: Atom) -> None:
-        ## TODO:
-        pass
+        if atom.name in self.inodes:
+            self.inodes[atom.name].applyAtom(atom)
+        else:
+            cont = atom.cont
+            type = ["dir","file"][cont[b't']]
+            inode = Inode(atom.name, self.iotaApi, self, type)
+            self.inodes[atom.name] = inode
 
     def _newAtom(self, atom: Atom) -> None:
         self.append(atom.dump())
@@ -264,11 +269,8 @@ class TangleFileTreeElement(TangleBlob):
         self._requireFetched()
         if name in self.getNameList():
             return False
-        atom = Atom()
-        atom.type="file"
-        atom.name = name
-        atom.token = self.genToken()
-        atom.size = 0
+        file = Inode(name, self.iotaApi, self, "file")
+        atom = file.change(size=0, milestoneIndex=0, hash=b'NULL')
         self._newAtom(atom)
         self._applyAtom(atom)
         return True
@@ -340,11 +342,12 @@ class Inode():
 
     def change(self, size: int=None, hash: int=None, milestoneIndex: int=None) -> Atom:
         delta = {}
+        delta[b't'] = (self.type=="file")
         if size!=None:
             self.size = size
             delta[b's'] = size
-        if size!=None:
-            self.size = hash
+        if hash!=None:
+            self.hash = hash
             delta[b'h'] = hash
         if milestoneIndex!=None:
             self.milestoneIndex = milestoneIndex
@@ -359,6 +362,8 @@ class Inode():
             if self.name in stones:
                 self.applyAtom(Atom(False, stones[self.name], self.name))
         else:
+            if (self.type=="file") != atom.cont[b't']:
+                raise Exception("I am a "+self.type+"; this atom is for the other thing")
             delta = atom.cont
             if b's' in delta:
                 self.size = delta[b's']
@@ -376,9 +381,9 @@ class Inode():
             return None
         if not self.ref:
             if self.type=="dir":
-                self.elem = TangleFileTreeElement(self.name, self.milestoneIndex, self.parent, self.iotaApi)
+                self.ref = TangleFileTreeElement(self.name, self.milestoneIndex, self.parent, self.iotaApi)
             elif self.type=="file":
-                self.ref = TangleFile(self.name, self, self.api)
+                self.ref = TangleFile(self.name, self, self.iotaApi)
             else:
                 raise Exception("Cannot get reference of an inode of type "+self.type)
         return self.ref