In a parallel universe the Faithful believe that the Futama will deliver them from the despotic empress, Prua Landi. They send emissaries back in time, who persuade Joe Laing to exchange his life in the early twenty-first century for an era seven-hundred millennia into his future. In that distant time Prua Landi is attempting to exterminate every member of the Faithful sect. Joe is captured, and the empress tortures him with powerful mental probes before killing him with a violent telepathic thrust. The vile act is witnessed by Sennit, a palace servant. The empress steps up her systematic extermination of the Faithful, unaware that an enclave has survived, hidden within an underground complex. The survivors are barely managing to maintain their existence on little more than starvation rations. The death of their legendary leader has been a bitter blow, but even so they refuse to abandon hope of salvation from Prua Landi's tyranny. The Faithful develop a daring plan to enlist the help of a Futama from a parallel reality, and so begin research towards their goal. Prua Landi hears rumours of the research, and realises that if separate realities exist, she must beat the Faithful to the prize. If she eliminates the Futama in other universes, she can expand her empire. The race is on Sennit had found sanctuary in the one place where the empress would never consider looking for members of the Faithful: within her palace. Three years have elapsed since the Futama's death, and when Sennit hears the empress and her cousin discussing plans for research into parallel realities, he absconds and seeks the last Faithful stronghold. After many months Sennit reaches the underground complex, and at first he is treated with suspicion. He insists that he brings vital information, and is taken for interrogation. After questioning under a voluntary mind probe, Sennit tells the Faithful that the empress has begun research into parallel realities, using all the resources at her disposal. The bio-engineer reveals that he is an expert in advanced artificial intelligence, and he rejuvenates the enclave's aging AI. Sennit then proceeds to grow a specialist artificial intelligence, which leads to the breakthrough they desperately need. The Faithful develop a dimensional transfer machine, and the first attempt to send a monitor through the portal causes alarm in the target universe, where controls are quickly set up to prevent wholesale transfers between realities. Gillane, head of the government, insists that Joe Laing must be persuaded to accept their protection, in case another version of Prua Landi is responsible for the inter-dimensional portal. Once Joe and his family are safe, the restrictions are temporarily removed to permit the passage of the monitor, and then immediately reactivated. The first, human to crossover is Roma, who begs for help to end Prua Landi's tyranny. When Joe learns about the situation he knows he must help Roma's people. No one doubts that what has already been achieved will be duplicated by Prua Landi, which means that she will attempt to kill Joe and his family. Joe must enter the parallel universe and end Prua Landi's reign of terror in order to prevent all-out war. The survivors in the enclave are supplied with food and medicine, and over a period of weeks, Joe trains the fittest survivors in martial arts skills. Prua Landi's first transfer returns instantly, claiming his arrival has been anticipated, and this forces the empress to relocate her transfer point. She finally enters the alternate reality intending to kill Joe, but discovers that he can easily resist the power of her mind. She flees back to her own reality and destroys the portals so that no one can pass through. When the enclave is at last located by Theda Lan's agents, the empress orders her forces to attack, and Joe must lead his people in a final battle to decide the fate of both worlds.