A country awash with paranoia and conspiracy - but a safe haven for a radical monk on the run. Giordano Bruno, with his theories of astronomy and extraterrestrial life, has fled the Inquisition for the court of Elizabeth I. Here, he attracts the attention of Francis Walsingham, chief spymaster and sworn enemy of Catholic plotters.
Bruno is sent undercover to Oxford, where the university is believed to be a hotbed of French dissent. Bruno quickly finds himself drawn into college intrigues, and distracted by a beautiful young woman. Before long, he is investigating a hideous series of murders, each linked by a letter offering clues. The letters suggest that each victim was guilty of heresy. But is Bruno being aided or misled - or is he himself the next target? Stalking a cunning and determined killer through the shadowy cloisters of Oxford, Bruno realizes that even the wise cannot always tell truth from heresy. But some are prepared to kill for it.