About the BookBobby Pendragon and Vo Spader, the Traveler from Cloral, arrive on First Earth (New York City, 1937) shortly after the death of Bobby's uncle, Press Tilton, by bullets from gangsters that Saint Dane has hired. They meet the First Earth Traveler, a bell captain at the Manhattan Tower Hotel named Vincent "Gunny" Van Dyke. Bobby and Spader become employed as bellhops there, and investigate the ties between First Earth's Turning Point, rival crime godfathers Max Rose and Winn Farrow, and the Nazi party.
The critical connection is revealed to be the Hindenburg zeppelin. To understand its significance, Bobby and Gunny visit Third Earth, in the year 5010. The Traveler Patrick accesses a computer that predicts the future in which they save the Hindenburg: industrial spies working for Max would lead to the Nazis developing an atomic bomb and winning World War Two.
Bobby and Gunny return to First Earth, only to find that Spader and Rose have gone ahead, seeking to stop Winn Farrow from shooting a firework rocket into the dirigible. Bobby is flown to the LZ-129's launch site by a female aeroplane pilot called Nancy Olsen (alias Jinx), who has been his client at the Hotel. There, he commandeers Max Rose's car and drives to the rocket's launch pad. Spader, misunderstanding, tries to stop the rocket from launching; Gunny holds him back. Looking up, Bobby sees the faces of those who will die in the explosion and is reluctant to let them die. Gunny again intervenes, holding him until the rocket launches and the zepplin burns.
Full of angst over his role in the tragedy, Bobby returns to his home on Second Earth (the twentieth and twenty-first centuries) for a pause in his Travels. Without any family, he lives with his friend Mark Dimond, who is a confidante or "acolyte" of the Travelers. Later, he travels with Gunny to Veelox, leading into The Reality Bug.