" Josh Thomas was sitting in Egan’s study, reading a chemical analysis journal, when he froze in fright. The rug in the center of the room suddenly rose from the floor as if a ghost were inside and then flew aside. A trapdoor beneath swung open and Pitt’s head popped up like a jack-in-the-box. “Sorry to intrude,” said Pitt with a cheery smile. “But I just happened to be passing by. "

― Clive Cussler , Valhalla Rising (Dirk Pitt, #16)