He is condemned by the Empire to the planet Shayol, where he lives in a penal colony whose inhabitants must undergo grotesque physical mutations caused by tiny symbiotes called dromozoans.

The bull-man B'dikkat administers the prisoners a drug called super-condamine that alleviates the pain of their punishment and various surgeries.

B'dikkat shows the couple a sight that horrifies him: children have been sent to Shayol -- alive, though with their brains removed.

They will free the prisoners who are still sentient and provide a cure for their suffering with a substitute for the super-condamine, namely an electronic "cap" which stimulates the brain's pleasure center.

The mindless prisoners will be decapitated, their heads "taken away and killed as pleasantly as we can manage, probably by an overdosage of super-condamine", leaving the bodies to be used by the dromozoa.