Constructed for an unknown purpose by a long-dead race called the Veil, Shellworlds are ancient artificial planets consisting of nested concentric spheres internally lit by tiny thermonuclear "stars".

It becomes increasingly clear that they are searching for something hidden in the Nameless City, a metropolis buried under several hundred million years of sediment which is currently being stripped away by the giant Hyeng-zhar waterfalls.

Arriving at Sursamen on board the Liveware Problem, the team (Anaplian, Hippinse, Ferbin, Holse and Xuss) successfully infiltrate their way down to the Shellworld's ninth level to confront tyl Loesp, and protect their brother, Prince Oramen, both of whom are overseeing the excavation of the Nameless City.

By the time the team arrives, Oramen has survived assassination attempts by tyl Loesp, but has been killed by a mysterious and powerful entity long entombed in the ancient ruins.

The liberated Iln machine's nature is a horrible surprise to the Sarl humans and especially the Oct, who thought that they were excavating one of the "Involucra" (aka the Veil) who had originally built the shellworlds and from whom they claim to be descended.

The Iln entity kills all nearby Sarl and Octs - including both Oramen and tyl Loesp - with a small thermonuclear explosion—after thanking them for their help—and heads towards the core of the Shellworld, planning to capture the Xinthian "WorldGod" and then destroy Sursamen by generating and detonating antimatter.

The Liveware Problem itself speeds down a vast shaft into the Shellworld's interior to lead the team, but sustains substantial damage from Nariscene weapons during its descent to the core (it becoming increasingly apparent that all the various species involved have been getting their hands on technology from at least one level higher up the chain).

Despite her advanced armour, she is eviscerated beyond the point where a non-SC enhanced human would be dead, but she remains conscious enough to detonate the tiny grain of antimatter in her skull that provided power to her SC-enhanced body, destroying the Iln entity and saving the Shellworld.

In the epilogue, Holse, the lone survivor of the Iln encounter, rejoins his family after a long absence, accompanied by the surviving Liveware Problem avatoid, Quike.

An unused section of the first draft was published as the short story 'The Secret Courtyard' in a booklet called 'The Spheres', by the Birmingham Science Fiction group, in 2010, in a limited edition of 500, to mark Novacon 40.