The 31-minute Fox Movietone "featurette" The Knife was adapted from the one-act play of the same name by Henry Arthur Jones. Lionel Atwill plays Dr. Ridgeway, a celebrated London surgeon who reluctantly agrees to perform a delicate and dangerous operation. The patient is Ridgeway's best friend, who may or may not be carrying on an affair with the doctor's wife (Violet Heming). When it turns out that his suspicions are correct, Ridgeway stoically enters the operating theater -- but will he honor his Hippocratic oath and save his friend's life or vengefully let his hand slip, thus ridding himself of an unwanted rival? The answer is left for the audience to decide. The Knife was directed by Thomas B. Chalmers, who also helmed the classic Robert Benchley one-reeler The Treasurer's Report (1928). ~ Hal Erickson, All Movie Guide