 Why was Don unable to shower while on Superior?
Radio messages stated simply that Superior had seceded from Earth. Communicating by radiophone across the vast pit, they confirmed that the town undoubtedly was missing. A National Guard officer volunteered to take a jeep down into the pit, having found a spot that seemed navigable. One other radio message came from Superior, now airborne, on that first day. Don Cort had been dozing in what passed for the club car on the Buckeye Cannonball when the train braked to a stop. When Don had entered the club car he'd seen her hatless head from above and noticed that the hair along the part was dark. Don hesitated, shrugged at the redhead, said, "Excuse me," and followed the conductor. Don made his way up to the locomotive and found a bigger knot of people gathered in front of the cowcatcher. Don saw two men who must have been the engineer and the fireman talking to an old bearded gentleman wearing a civil defense helmet, a topcoat and riding boots. Don Cort and the fireman walked cautiously toward the edge while the professor ambled ahead with the familiarity of one who had been there before. He didn't have to stand on tiptoe any more than he had to sit on the edge of his seat during the exciting part of a movie, but the situation seemed to call for it. Well, Professor Garet telephoned and said, 'Hector'—that's my name,
 He was unable to remove the briefcase in order to remove his clothing,
 He feared that someone would steal the briefcase if he left it unattended.  The water supply was lacking from the stream flowing out of Superior.  There was an electrical current flowing throughout the water in Superior.  He was unable to remove the briefcase in order to remove his clothing,