Callum is a mutual friend of Dexter and Emma who goes into business and eventually becomes the head of a health food company. He offers Dexter a job after Dexter’s television career ends, but Callum is condescending and has an affair with Dexter’s wife at the time, Sylvia. Callum ultimately seems to regret ending up with Sylvia, showing how the pursuit of status and success for its own sake can be meaningless.