London, 1929. Frank Webber, a very busy Scotland Yard detective, seems to be more interested in his work than in Alice White, his girlfriend. Feeling herself ignored, Alice agrees to go out with an elegant and well-mannered artist who invites her to visit his fancy apartment.
Three sideshow performers form a conspiracy known as "The Unholy Three" - a ventriloquist, midget, and strongman working together to commit a series of robberies.