A bomb-maker who calls himself Mystère has been destroying corporate admin buildings on various worlds, and Deven has cut short Nyx's vacation and ordered her to find him and kill him. She has little data to guide her, but encounters an amnesiac young woman dubbed Zinc at one of the blast sites. Zinc may possess information that could lead to Mystère, if only she can be made to remember. Meanwhile, an intrigue within Amphictyony Security has replaced Deven with a look-alike, and threatens to turn Blacklight Section against itself. Rogue agents have been dispatched to turn Nyx or kill her. Isolated, and under impossible orders, Nyx has few resources to marshal . . . until a surprise from her past shows up at her door.