It's been several months since the events of The Yellow M, but the evil of Professor Septimus still echoes around London. Important figures of the capital's jet set come together around the questionable values the mad scientist defended. Olrik is forced to resort to opium in order to forget he was guinea pig. As for Mortimer, he too is trying, albeit for more humanist reasons, to revive certain aspects of Septimus's work-to Blake's extreme concern...