Emil und die Detektive (Emil and the Detectives) (1931)

No less a scrivener than Billy Wilder adapted the Erich Kastner novel Emil and the Detectives for its first film version. The story concerns a young boy named Emil who has been packed off to visit relatives in Germany. While en route on the train, Emil's money is stolen by a penny-ante thief. The boy enlists the aid of a group of pre-teen youths who fancy themselves ace detectives. The kids get in deeper than expected when it turns out that the thief is part of a criminal gang planning a big heist. The 1931 Emil and the Detectives is perhaps the best of the four film versions of the Kastner story, benefitting from some cheerful glimpses of a sunshine-drenched Berlin that disappeared forever during World War II. Subsequent versions of Emil would be filmed in England in 1935, in West Germany in 1954, and by Walt Disney (who couldn't resist the temptation to "Americanize" the characters) in 1964.