London, 1817. An impatient crowd is gathered outside the stage door of the Covent Garden Theatre, desperate for a glimpse of actress Hannah Granville after her latest performance as Lady Macbeth, amongst them the Prince Regent himself. But before she can appear a gunshot sounds, and a man lies dead on the ground amidst the ensuing chaos.

Sir Roger Mellanby MP had been a spearhead for social reform, although his political leanings had made him many enemies within the Westminster elite and even in his own family. But was he really the intended target of the shooting? After a curt dismissal from the Bow Street Runners, Mellanby's friend Seth Hooper engages the services of twin detectives Paul and Peter Skillen to investigate the killing.

Elsewhere, the assassin's own problems are just beginning.