When a local goldsmith, Godfrey of Harwood, is found brutally murdered in his home, Furnshill and Puttock are called on to investigate. But when rumors begin spreading that patients from a local leper hospital might have been involved in Godfrey's murder, a series of vicious attacks on the unfortunate victims ensues, culminating in a disastrous fire at the hospital. In a surprising turn of events, Godfrey's daughter Cecily donates a sum to make good the damage. Her connection to one of the lepers is her motive, and only when that connection has been revealed will the truth about Godfrey's murder emerge.