The third Denton mystery centres on political intrigue, terrorism 1900s-style and the beginnings of the British Secret Intelligence Organisation, as London becomes a hotbed of anarchist plotting. Denton is drawn into a complex web of murder and revenge when a mysterious Polish woman is found dead in the house adjoining his - the one occupied by his lover, Janet Stryker - and while the police remain baffled, he begins to suspect she is the victim of some sort of political conspiracy. But involving himself in the life and death of Lydia Alken will prove more dangerous than he could have imagined, as Denton himself falls victim to the fledgling British Intelligence Service and discovers exactly what the price of freedom really is, while the real story of Lydia Alken's murder provides the biggest shock of all.