The series is mainly set in London, where the protagonist lives, though he occasionally travels elsewhere. His clothes are one of his defining characteristics: he always dresses the same way, in a red shirt, black jacket, and blue jeans; he bought twelve identical outfits after the death of his lover Lillie Connolly. One of the principal supporting characters in the series is his assistant (or rather, comic relief), Groucho, a punning double of Groucho Marx. Another supporting character is Inspector Bloch, who was his superior when he worked at Scotland Yard and remains his father figure (in fact he calls Dylan "Old boy") even after Dylan struck out on his own to become a private investigator specializing in the supernatural.