Crest and his companions find themselves transported to a desolate, dying planet inhabited by insectoid creatures pursuing a dangerous mission under the yoke of the Arkonides: complete a superweapon for use against the Methanes. While investigating, they discover a more familiar species-the Ilts-being oppressed by their hosts. Meanwhile, Manoli and his companions have fallen ill. The mysterious sickness is thought to be linked to their time as Besun, but relations between the Fantan and Earth are fragile. Can the Fantan save their former captives' lives?

Elsewhere in the galaxy, Rhodan's crew find themselves stranded in time and space on Ambur, the Vega system's mysterious tenth planet, a hostile wasteland with pockets of civilization. What are Rhodan, Thora, and the others expected to give in return for their rescue by its inhabitants? And can the strangers cure the strange affliction tormenting Bull and Sue?