When Socialite Iris’ unexpected travelling companion suddenly disappears, Iris is perplexed to find that all the other passengers deny ever having seen her. But with the help of musician Max, she turns detective, and together they try to solve the mystery of why the lady vanished… Building on the phenomenal decade-long success of The Agatha Christie Theatre Company, The Classic Thriller Theatre Company presents a quick-witted and devilishly fun thriller, based on the 1939 Hitchcock classic, ranked as one of the best British films of all time.