Marooned on the artificial planet Terminal, Avon, Vila, Dayna and Tarrant finds their only hope of rescue is the space freighter Scorpio commanded by Dorian and his associate, Soolin, the blonde gunfighter from the lawless planet Gauda Prime.
The Xenon base security systems have locked down the Scorpio, effectively stranding our heroes. The computerized lock leading to the launch silo can only be opened by Avon, who has his hands full after becoming enmeshed in a war between the male Hommiks and the female Seskas. And if that wasn't bad enough, there's a nuclear weapon counting down inside the launch silo...
When Avon receives news Helotrix has been reconquered by the Federation, Scorpio travels to the planet to find out how they were defeated so easily. Tarrant and Dayna meet up with the local resistance group and encounter an old enemy.
Scorpio is damaged in a collision course with a asteroid and the Scorpio crew require a star-drive from Federation scientist Dr. Plaxton so they can out-run all Federation pursuit ships. Only to find Dr. Plaxton is working for space pirates "The Space Rats".
Avon sets out to recruit Justin, one of Dayna's former tutors and former lover who is conducting genetic engineering experiments. But Serverlan captures Dayna and brainwashes her into hating Justin and forces Justin share with her his discoveries on his experiments.
The rebels help a top cybernetic scientist, Muller, to defect from the Federation. Whilst escaping, they discover a dead body and a mysterious box which terrifies Muller, leading to a disastrous struggle and quarantine for the Scorpio crew.
Vila intercepts a message from Sleer, endlessly repeating "Utiliser to Cancer. Domo the 9th. Five subjects". According to Avon, Cancer is an infallible assassin. Orac's advice is to find and kill Cancer first, before he hunts them down.
The Federation sends Commissioner Sleer to Mecron II in order to investigate the various irregularities discovered in the mining operation on that planet. Belkov, the head of the mining unit, has hidden a large consignment of crystals aboard his orbiting space station. But Avon and his accomplices are also after the crystals, assisted by one of Belkov's erstwhile colleagues.
Marooned on the arid desert world of Virn, Tarrant and his enemy must confront each other, and the past, whilst trying to solve the mystery of a lost Federation expedition. Meanwhile, time is running out for the struggling Scorpio and Orac.
Keiller, an "old friend" of Avon, proposes an ingenious heist to make off with a huge Federation gold shipment. All it requires is the Scorpio, the Space Princess pleasure cruiser, an infiltration mission, and for nothing to go wrong.
The Scorpio crew are summoned by Renegade Federation scientist Egorian who wants to unleash vengeance on the Federation. Egorian wants to trade a powerful weapon in exchange for Orac. But Avon and Vila discover Egorian is working for Serverlan in another bid to take Orac, unaware Avon has given Egorian a fake duplicate of Orac.
Orac has pinpointed Blake's location and reveals to Avon and the crew of Scorpio that he is on the lawless planet Gauda Prime, where Blake has given up fighting against the Federation and is now a bounty hunter. But the crew of the Scorpio suspect Blake has betrayed them and has sold out to the Federation.