They cooperate in solving the murder and recovering the diamond.
After the murder and theft, Sherlock Holmes and Inspector Lestrade jointly question passengers and investigate the train.
Holmes investigates Duncan-Bleek as the concealed force behind the crimes.
Holmes suspects that someone on the train is the notorious jewel thief, and later informs the alleged Scottish inspector that Duncan-Bleek is secretly...
Holmes protects Lady Margaret's interests by tracing the stolen diamond.
Holmes briefly examines the diamond owned and transported by Lady Margaret Carstairs, and his investigation centers on its theft and recovery.
Vivian's coffin and testimony provide Holmes with essential investigative clues.
Holmes searches the coffin being transported by Vivian Vedder and later considers her statement that a man paid her to carry it.
Explore the full interactive character relationship map of Terror by Night
Related entry on Wikidata (Q4653), public domain (CC0).