In October 1814, former investigator Sir Edwin Pym is killed in a manner that echoes the Ratcliffe Highway murders of 1811. Those earlier killings ended after sailor John Williams died in custody, but the new death suggests that the wrong man may have been blamed.
Sebastian reopens the old case while further victims connected to the original investigation are attacked. Conflicting testimony, damaged evidence and official certainty conceal a killer who has waited three years to remove the people capable of exposing what really happened.