Sylvester Collins

Mabel Watson

Mabel and Sylvester share a deep romantic connection, with frequent interactions suggesting a secret or intense affair.

Arthur Sinclair

Arthur and Sylvester are locked in a bitter rivalry, likely over Mabel or professional standing.

Eric Sanders

Eric is a close friend and ally to Sylvester, often supporting him in his schemes or investigations.

F. D. Boyce

Boyce is a professional or personal antagonist to Sylvester, frequently clashing with him.

Mr. Allery

Mr. Allery is a superior or authority figure who interacts with Sylvester in a formal capacity.

Mrs. Simmons

Mrs. Simmons is a neighbor or acquaintance who keeps tabs on Sylvester's activities.

Lewis

Lewis is a minor acquaintance of Sylvester, possibly a servant or messenger.

Mabel Watson

Mabel and Sylvester share a deep romantic connection, with frequent interactions suggesting a secret or intense affair.

Arthur Sinclair

Arthur and Sylvester are locked in a bitter rivalry, likely over Mabel or professional standing.

Eric Sanders

Eric is a close friend and ally to Sylvester, often supporting him in his schemes or investigations.

Mabel Watson

Mabel and Sylvester share a deep romantic connection, with frequent interactions suggesting a secret or intense affair.

Arthur Sinclair

Arthur and Sylvester are locked in a bitter rivalry, likely over Mabel or professional standing.

The Wrong Letter

Collins is present with Mabel and examines the wrongly delivered letter.

I: The Crime

Amateur detective who arrives at Scotland Yard after receiving a mysterious phone call; accompanies Sinclair to the crime scene and takes charge of the investigation.

II: Speculations

Hosts the discussion, outlines the four possibilities for the crime, and decides to investigate Mrs. Simmons further.

At the Vale

Travels to The Vale to inform Mabel of her father's murder; observes the household and gathers information about Eric Sanders and Ronald Watson.

IV: The Missing Letter

Mentioned in Sir James's letter as a theorist not to be consulted; sends a wire to Sinclair asking him to wait.

A Mysterious Visit

Collins debates with Sinclair about Lewis's guilt, attends an opera, and discovers a familiar face in a miniature portrait.

VI: At Leveson Square

Arrives at Leveson Square with Sinclair; questions the doctor about the bullet; confronts Boyce about press leaks; receives a telegram from Miss Watson.

VII: Valuable Information

Meets Mabel at Paddington, invites her to the theatre, confronts Mrs. Simmons about her perjury, and probes Sanders about the murder.

VIII: Enter Mr. Allery

Helps with funeral arrangements and gains Mabel's trust; learns about Sir James's will from Allery.

A Confession

Dismisses Jackson's confession as the product of a lunatic and accuses Boyce of using him as a scapegoat.

X: The Portrait

Arrives at Wilton-on-Sea, observes Eric's transformation, reacts to the portrait, and later examines it alone.

XI: An Apparition

Shows growing interest in Mabel; calmly investigates the ghost sighting and offers a rational explanation; observes the reactions of others closely.

XII: What Happened in the Night

Investigates footprints on the rug, confronts Eric Sanders, and decides to leave the party.

XIII: The Car in the Dark

Investigates the attic room, warns Mabel about Sanders, and later spies on a secret nighttime car ride.

XIV: Back in London

Collins returns from Devonshire looking gaunt and hints that he knows the true murderer, but says the man 'doesn't exist,' leaving the others baffled.

XV: The Crisis

Arranges the meeting at The Vale, reveals his deductions about Watson's identity and hiding, and explains his investigation.

XVI: The Criminal Found

Revealed as the prime suspect; Sinclair details his clever ruses and growing evidence against him.

XVII: The Wrong Letter

Revealed as the master criminal blackmailer and murderer of Sir James Watson.