The Drax contamination Karloff sustained in book 2 of the series continues to lie dormant in his body, while Medina battles mutants who threaten the city from the inside, and fends off ever-greater attacks to its exterior. The city's protective dome is at risk of total collapse. Kladia strikes off into the desert to find a better life, while Hadron, pregnant with Drax leader Boso 1's offspring, makes a bold decision that might alter the course of history...