Harrison has learned to wear many hats during his years in the entertainment industry. Writer, director, producer, and actor can all be found in his work experience both in American and Canadian productions for television and film. Beginning in the mid 1980s, the British actor took small television roles including police officers, doctors, and members of the military. As a character actor, he has appeared in episodes of "The X-Files" and "Cold Squad" with a pension for science fiction and thriller roles. Harrison has also taken on jobs behind the camera throughout the course of his career. His writing credits include the 2001 crime drama "Dark Water." He also directed and starred in the 1998 film "Saving Grace" as Joseph Briteman, a disfigured man who gets taken advantage of in his personal and professional life. The film remains his most popular motion picture role as a lead character. Moving into American television, Harrison has appeared in several successful series in the 2000s, including "Supernatural," "Psych," and "Fringe." his most notable American roles are that of Ritchie in 2007's "AVPR: Aliens vs Predator - Requiem" and as a doctor in the 2005 thriller "White Noise," continuing his casting in films that deal with the supernatural.