In Moria, in Balin's tomb, Gandalf hands Pippin his hat and his staff so he can read the book. When Pippin knocks the skeleton down the well (fool of a Took!), Gandalf takes both the staff and the hat back. But just a few minutes later, when the orcs come into the tomb, and then when they are running from the orcs, Gandalf's hat is nowhere to be seen. He isn't wearing it and he isn't carrying it. What happened to Gandalf's hat??