Terror by Night

In London, Vivian Vedder arranges for her mother's coffin to be transported to Scotland and boards the train that will carry the passengers. Lady Margaret Carstairs, her son Roland, Sherlock Holmes, Inspector Lestrade, Dr. Watson, and Major Duncan-Bleek accompany them, along with the Star of Rhodesia diamond. The stage is set for a tense journey as the precious cargo and the passengers become entwined in a growing mystery.

Holmes briefly examines the Star of Rhodesia, sizing up the jewel and noting potential vulnerabilities. His observations hint at possible misdirection and establish the diamond as the central motive for the unfolding crime. The passengers sense an expert eye watching the case as the train becomes a moving crime scene.

Shortly after departure, Roland is killed and the famous diamond disappears. The murder immediately turns all passengers into suspects and raises questions about who could have had access to the jewel and the coffin. Holmes and the others must navigate conflicting alibis while the train speeds toward its destination.

Lestrade, Holmes, and Watson question the other travelers, but no conclusive evidence emerges. The group encounters contradictory stories and small acts of deception that keep the real thief hidden. The investigation stalls as the puzzle deepens rather than resolves.

Watson fixates on an elderly couple as possible culprits, yet their only crime turns out to be stealing a teapot—harmless in itself. The moment illustrates how appearances can mislead and underscores the danger of assuming guilt without hard proof. Holmes continues to piece together the larger pattern behind the theft.

During the investigation, Holmes is forced from the moving coach but manages to climb back aboard. He discovers a secret compartment concealed within the coffin carrying Miss Vedder's mother. The discovery reveals a hidden layer to the crime and a possible means for concealing or transporting illicit loot.

Vedder admits that a man paid her to transport the coffin, shifting responsibility to an external patron. The admission points to a broader conspiracy and prompts suspicion toward those who stand to gain from the theft. The mystery shifts from a straightforward jewel theft to a more intricate plot involving paymasters.

Holmes reveals that he swapped the genuine diamond with an imitation during his examination. The ruse complicates the evidence trail and buys time to confront the thieves. Lestrade assumes he has possession of the real diamond, setting up the next confrontation.

A guard is murdered with a poisoned dart in the luggage compartment, and the street criminal Sands is hidden inside the coffin, working with Major Duncan-Bleek—who is, in fact, Colonel Moran. The layers of deception tighten around the diamond once more as Moran's identity begins to emerge.

Sands and Moran confront Lestrade in his room; Sands is knocked unconscious and the diamond is stolen from Lestrade. Moran double-crosses Sands, shooting him with the same poison dart used earlier. The betrayal accelerates the confrontation and reveals how dangerous the plot has become.

The train stops to pick up Scottish policemen led by Inspector McDonald, whom Holmes identifies as a fake when he points out that Duncan-Bleek is Moran. McDonald arrests Moran and finds the diamond tucked in Moran's vest, temporarily restoring order on the railcar.

Moran seizes a policeman's gun and pulls the emergency cord to halt the train. The sudden halt throws the passengers into confusion and sharpens the focus on who truly holds the diamond. Holmes uses the moment to keep Moran under surveillance.

In a blackout, Holmes subdues Moran and handcuffs him, concealing the criminal beneath a table. The operation demonstrates Holmes's tactical command and his ability to control a chaotic scene without alerting the others.

When the lights return, the officers depart with Lestrade, believing him to be Moran, while Moran remains hidden and the real thieves continue to be pursued. The confusion highlights the fragility of the official narrative aboard the moving train.

As the train finally departs, the thieves are cornered at the railway station and Lestrade is captured by his own misidentification. Holmes explains to Watson and Moran that he recognized McDonald as the impostor and recovers the diamond from him during the confrontation, ending the case.