The Lady Vanishes (2013)

Rich socialite Iris Carr cuts short her holiday in the Balkans and decides to return to London. She has a fainting spell and nearly misses her train. Once on board, she is somewhat disoriented and finds herself sharing a compartment with a Baroness and her entourage. Among them is an Englishwoman, Mr. Froy and the two of them take tea. Miss Froy works as a governess for a member of the Baroness' family. After taking a nap, Iris awakens to not only find that Miss Froy is missing, but everyone around her insisting no such person was ever on-board. Iris is certain of her existence and works with another passenger, Max Hare, to solve the mystery.