Murder Ahoy

An observant, sharp-witted elderly sleuth who boards the ship to uncover the truth about the trustee's death and the subsequent murders. She relies on patient observation, careful inference, and a calculated trap to reveal the killer. Her calm confidence and fencing skill help neutralize the threat and bring the culprit to light.

Captain of HMS Battledore, he resists Miss Marple's intrusion and defends naval propriety. His affair with the ship's matron complicates his standing and motives. Although cleared by the board, he chooses to resign to preserve propriety as he plans to marry.

First Mate Breeze-Connington is the murderer's public face and the embezzler behind the crimes. He confesses to siphoning funds over years to cover up his failures and intends to kill Marple to keep the secret. His arrogance and sword-skill make him a dangerous adversary until Stringer intervenes.

Miss Marple's confidante on shore who tracks the sailors and brings critical information back to her. He helps expose the embezzlement scheme and intervenes at a pivotal moment to thwart Breeze-Connington.

A lieutenant who overhears discussions and moves to warn the Captain, but is murdered with a sword before help can arrive. His death raises the stakes and emphasizes the reach of the killer among the crew.

Chief Inspector Craddock oversees the on-board investigation, coordinating with Marple to uncover the killer and motive. He orchestrates the trap that lures the murderer ashore while the crew is off ship, restoring order after a series of betrayals.

Assistant Matron Shirley Boston serves within the ship's hierarchical structure and becomes a victim in the poisoning plot, heightening the sense of danger aboard the vessel.

Miss Pringle is a staff member whose presence adds to the ship's close-knit social network, contributing to the ensemble dynamics that reveal loyalty and deception among the crew.

The ship's doctor who provides medical context to the poisoning plot and aids the investigation through forensic insight.