He speaks the elf word for friend and the door opens. They step into the dimness and Sam weeps as the pony rushes away with Gandalf's bidding. The waters of the lake begin to seethe and a long dark tentacle strikes out and grabs Frodo's leg. The others rush into the caverns and Sam slashes at the limb, clutching Frodo. Gandalf says a word and the doors close.
Outside rocks tumble and it is closed for good.
The wizard makes a light with the end of his staff and they begin to march. After a while they stop and eat. Gandalf thinks it is forty miles to the other side. He walks ahead with his glowing staff and they follow behind him. Gimli is amazed by the tall and intricate passages.