The d'Alemberts are challenged by a savage hoax that has planted doubles of Jules and Yvette throughout the Empire, luring other agents to a cataclysmic doom. Beyond this tactic of terror the DsPlainians uncover an awesome conspiracy flung far and wide among the stars.

In the fight of their lives, the masters of the Circus must battle their way out of the deathmaze of an enemy battlestation - and vanquish a living asteroid that has become the fortress of an immortal human brain!