Mr. Samuel Copperdock

Part I: The Crimes

Reports the black sailor and later dies.

The Street

Old Sam Copperdock, Mr. Tovey's oldest friend and Ted's father, mentioned as a neighbour and friend.

II: The Herbalist

The tobacconist, a friend of Ludgrove, who eagerly shares news about the murder of James Tovey and the police investigation.

III: The Inquest

Attends the inquest, escorts Mrs. Tovey and Ivy home, and discusses the case with Mr. Ludgrove. He harbors suspicion about Wal Snyder and the Express Train gang.

IV: The Poisoned Pipe-Stem

Visits Ludgrove late at night, distressed about Ben Colburn's death and the discovery of numbered counters sent to both Tovey and Colburn.

V: Inspector Whyland

Visits Ludgrove after Whyland leaves, anxious about police suspicion. Ludgrove reassures him, and he gradually returns to his normal routine, including visits to Mrs. Tovey.

VI: A Middle-Aged Poet

Informs Ludgrove of the murder and relays Inspector Whyland's message; expresses concern about the safety of the neighborhood.

VII: The Black Sailor

Claims to have seen the black sailor; is excited and agitated; becomes a suspect in Whyland's mind due to his knowledge of the crimes.

At No. 407, Praed Street

Mentioned as still running his shop in Praed Street; Martin briefly considers visiting him but decides against it to avoid being recognized.

IX: A Strange Affair

Mentioned as having known Martin and being evasive about his whereabouts; Whyland suspects him.

X: At Scotland Yard

Visits Ludgrove to discuss the Goodwin death, complains about police suspicion, and then returns in terror after receiving counter VI.

XI: The Sixth Counter

Finds the sixth counter on his bed, becomes hysterical, and refuses to stay alone. Later, he is interviewed by Inspector Whyland and resumes his routine under police watch.

XII: A Hypodermic Needle

Found dead in his room, killed by a hypodermic injection of poison; the needle broke off in his back.

Part II: The Criminal

A key figure in the investigation, Copperdock's actions and findings are central to the narrative.

XIII: Enter Dr. Priestley

The deceased whose death by poison is under investigation; his mind was reportedly unhinged.

XIX: A Discovery

Recently deceased; a knife similar to those used in earlier murders is found in his possession.

XXI: An Explanation

Described as a simple and not over-intelligent dupe upon whom suspicion was cast; his bone counters and envelopes were used in the murders.

XXII: The Death Chamber

Mentioned as the victim of the Black Sailor's scheme; the numbered counter found on his bed was delivered by a miniature crossbow, and he was killed by a potassium bullet fired from an airgun.

XXIII: The Will

Mentioned as a witness to the will and as a victim of the Black Sailor's machinations.