Milne was an early screenwriter for the nascent British film industry, writing four stories filmed in 1920 for the company Minerva Films (founded in 1920 by the actor Leslie Howard and his friend and story editor Adrian Brunel). These were "The Bump", starring Aubrey Smith; "Twice Two"; "Five Pound Reward"; and "Bookworms". Some of these films survive in the archives of the British Film Institute. Milne had met Howard when the actor starred in Milne's play "Mr Pim Passes By" in London.