Set in the year 2025, the story unfolds in a world where the vast majority of the human population has been forced into subterranean shelters known as "ant tanks." Within these claustrophobic environments, the inhabitants spend their lives manufacturing highly advanced military robots called "leadies." The people of the tanks live in constant fear, believing that a devastating global conflict between two massive blocs—the Wes-Dem and the Pac-Peop—is still raging on the surface. According to the official narrative, the world above is a wasteland consumed by radiation, deadly diseases, and perpetual combat.
This terrifying reality is reinforced by frequent broadcasts from their supreme leader, Talbot Yancy, who reports on the ongoing destruction and demands that production of the leadies continues without pause. However, this is a massive fabrication. In truth, the war ended thirteen years prior. The ruling elites of the former enemy factions have maintained this deception to keep the populace enslaved, while they themselves live in luxury on sprawling private estates, using the leadies as personal servants and security guards. The figure of Yancy is actually a mechanical simulacrum, a puppet whose speeches are written by propagandists known as Yance-men. The entire system is controlled by the calculating Stanton Brose.
The plot intensifies when Nicholas St. James, the president of the Tom Mix tank, finds himself in a desperate crisis. The community's chief mechanic, Maury Souza, dies from a pancreatic condition. To preserve any hope of survival, the tank's physician, Carol Tigh, freezes Souza's body in hopes that he can be revived if an artificial pancreas can be acquired. Without Souza's expertise, the tank faces the very real possibility of failing its production quota, which would lead to the entire community being dissolved. When official channels offer no help, a group of desperate residents collects money and coerces Nicholas into venturing onto the surface to find the organ, even threatening him with a bomb if he refuses. Reluctantly, Nicholas completes a hidden tunnel and emerges into the unknown, expecting to find the horrors described in Yancy's broadcasts.
Meanwhile, on the surface, a Yance-man named Joseph Adams is tasked by Brose to destroy a housing developer named Louis Runcible. Runcible has been housing former tank residents in large apartments; while still confined, they are no longer in the tanks. Brose suspects Runcible of leaking the truth—that the war is over—to the underground communities. To frame him, Brose uses a time-travel device to plant counterfeit alien weapons beneath Runcible's Utah construction site, sending them back centuries into the past so they appear to be archaeological finds. Adams is ordered to write fraudulent scientific papers to validate these artifacts, while his friend Verne Lindblom is the one who actually manufactures the fake objects.
Upon emerging from the tunnel, Nicholas lands on the property of David Lantano, another Yance-man. He is initially captured by leadies and nearly executed, but he is saved by a man who looks exactly like Yancy. Guided toward the ruins of Cheyenne, Nicholas meets other former tank inhabitants who reveal the shocking truth: the war ended long ago. While some radioactive zones still exist, the world is not the endless battlefield he was taught to fear. Lantano eventually takes Nicholas to his estate and offers his assistance in securing the necessary pancreas.
As the political intrigue deepens, Brose's plan begins to unravel. His agent at the construction site, Robert Hig, is killed after discovering one of the planted artifacts, and subsequent excavation destroys the evidence. Soon after, the artifact creator, Verne Lindblom, is murdered by an assassination machine designed to plant false evidence. Fearing that Brose is now eliminating everyone involved in the conspiracy, Adams seeks refuge at Lantano's estate. Simultaneously, an investigator named Webster Foote begins looking into Lindblom's death. Foote realizes the evidence against Brose was fabricated by a machine, and his investigation eventually leads him to Lantano's estate, where Nicholas is also staying.
Lantano reveals a startling secret: he is actually a Cherokee from the fifteenth century who discovered time-travel technology through the very artifacts sent back in time. Because of this technology, his physical age fluctuates, explaining why his older form resembles Yancy. Lantano harbors ambitions to overthrow Brose and take control of the system. He, Foote, and Adams conspire to assassinate Brose using a specialized dart weapon installed in Adams's office. However, Lantano privately confesses to Foote that he was the one who murdered Hig and Lindblom to manipulate Adams into wanting Brose dead.
Using equipment and leadies provided by Lantano, and guided by Foote's information, Nicholas successfully locates a buried medical depot and retrieves the pancreas. Meanwhile, Adams discovers Lantano's role in the murders and abandons the assassination plot. When Foote's guards attempt to force Adams toward New York, Adams orders his leadies to kill them. He then flees and joins Nicholas in the underground tank to hide. Back in the shelter, Carol Tigh successfully implants the organ, and Maury Souza is revived.
The story concludes with a delayed broadcast from Yancy announcing that the war has finally ended and promising that the people can gradually return to the surface. Nicholas and Adams assume that Brose has been killed, though the exact details of the power shift remain a mystery. The broadcast conveniently ignores the years of lies told to the people. While Adams worries about how to explain the existence of forests and luxury estates to the returning masses, Nicholas remains firm. He intends to tell the inhabitants of the tank the absolute truth, resolving that they must never allow themselves to be deceived by their leaders again.
