F/X (also known as or subtitled Murder by Illusion) is a 1986 American science fiction action thriller film directed by Robert Mandel, written by Gregory Fleeman and Robert T. Megginson, and starring Bryan Brown, Brian Dennehy, Diane Venora and Cliff De Young. The film follows an expert (Brown) in the art of special effects (F/X) with a reputation built by his work on many low-budget hack-and-slash films such as "I Dismember Mama". The Department of Justice hires him to stage the murder of a gangster about to enter the Witness Protection Program. He agrees, but then things get complicated. Meanwhile, a New York City police detective (Dennehy) is investigating the faked murder and cannot understand why the Justice Department is even less helpful than usual.