The Lady Vanishes is a 1938 British thriller film directed by Alfred Hitchcock, based on the 1936 novel The Wheel Spins by Ethel Lina White. The film stars Margaret Lockwood as Iris Henderson, Michael Redgrave as Gilbert Redman, and Dame May Whitty as Miss Froy.
The story begins with Iris and Miss Froy meeting on a train headed for England. Miss Froy is an elderly governess who is returning home to England after spending time in Europe. Iris is a young woman who is on vacation in Europe and is traveling back to England to marry her fiance. As the train travels through a mountainous region, an avalanche blocks the path, and the passengers are forced to stay at a hotel until the train can continue.
During their stay at the hotel, Iris and Miss Froy become friends, and Iris falls asleep while Miss Froy is playing a tune on her harmonica. When she wakes up, Miss Froy is nowhere to be found and no one on the train remembers seeing her. Iris becomes convinced that Miss Froy has been kidnapped or worse, and she enlists the help of Gilbert, a fellow passenger, to help her investigate.
As Iris and Gilbert search the train for clues, they encounter resistance from the other passengers, who seem to be hiding something. Soon, they realize that they are in danger and that they must solve the mystery of what happened to Miss Froy before it's too late.
The Lady Vanishes is a complex and suspenseful film, with Hitchcock's signature style of directing and storytelling on full display. The film has become a classic of the thriller genre and is still admired and studied by film scholars and Hitchcock fans today.