The chief protagonist, a typical Wallace anti-hero vigilante, one Henry Arthur Milton, aka The Ringer, a legendary assassin who killed for personal vengeance. The main character Inspector Wembury of Scotland Yard, who is having a very bad day. It is his first day as the new commander of Deptford Division; his immediate superior, the brutish, inappropriately named Chief Inspector Bliss, is back from America full of ideas like Tommy guns on the streets of London and a British FBI: his fiancée has just taken a job as secretary to a local lawyer Maurice Meister, an outwardly respectable but actually murderous criminal who Wembury knows - but cannot prove - was responsible for his fiancee's impressionable younger brother ending up doing a 4-year jail term for a robbery. Wembury's day is made miserably complete when the news is received that The Ringer, having been confirmed dead in Australia, is back in London and desiring vengeance against Maurice Meister, for Henry Milton left his only sibling, a much younger sister, in Meister's wardship when he left London and after Milton was supposedly confirmed dead her body was found floating in the River Thames.