Question: Which book, which is described by the author on its cover as a "thumping good detective-ghost-horror-who dunnit-time travel-romantic-musical-comedy-epic, was turned into a comic science fiction television series called Dirk Gently?
Sentence (from "Billy Boyle"): Lately he has been seen in Dirk Gently, for BBC Four and Lead Balloon.
Relevant evidence: No