 Already an actor in 1909, Boris Karloff attempted to enlist in the British Army during World War I, but was rejected due to his heart murmur.Wallace Ford and Reginald Denny, who played Morelli and Brown, had both served in World War I. Ford served in the United States cavalry, while Denny served as an observer/gunner in the Royal Flying Corps.Denny would eventually found a company that made radio-controlled target aircraft during World War II.