Episode Detail: Agatha Christie's Miss Marple: At Bertram's Hotel - Mystery!
In "Agatha Christie's Miss Marple: `At Bertram's Hotel' " (Part 1 of two), the sleuth (Joan Hickson) realizes that her fellow guests at a London hostelry share dark secrets, including the flamboyant Lady Sedgwick (Caroline Blakiston), who is overheard threatening to kill the doorman (Brian McGrath). Selina: Joan Greenwood.