The evil wizard Maldred has stolen the gold and silver keys which will allow him to release the Naga, the powerful earthquake dragon at the center of the earth--so Drake and several of the other Dragon Masters travel to the Naga's Temple in the Dragon Islands, to try and stop Maldred, and prevent him and the earthquake dragon from destroying the kingdom.

Arthur Penhaligon is supposed to die at a young age, but is saved by a key that is shaped like the minute hand of a clock. The key causes bizarre creatures to come from another realm, bringing with them a plague. A man named Mister Monday will stop at nothing to get the key back. Arthur goes to a mysterious house that only he can see, so that he can learn the truth about himself and the key.