The story picks up where the previous book left off, with Charlie and family aboard the flying Great Glass Elevator. The Elevator accidentally goes into orbit, and Mr. Wonka docks them at the "Space Hotel USA". Their interception of the hotel is mistaken by approaching astronauts and hotel staff in a Commuter Capsule and listeners on Earth (including the President of the United States) as an act of space piracy and they are variously accused of being enemy agents, spies and aliens. Shortly after their arrival, they discover that the hotel has been overrun by dangerous, shape-changing alien monsters known as The Vermicious Knids. The Knids cannot resist showing off and reveal themselves by using the five hotel elevators (with one Knid in each of them) and spell out the word "SCRAM", giving the group time to evacuate. As the group leaves, a Knid follows the Great Glass Elevator and tries to break it open, but to no avail, which results in the Knid receiving a bruise on its backside and hungering for payback.