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 "Dirk Gently (TV series)"): Dirk Gently is a British comic science fiction detective television series based on characters from the novel "Dirk Gently's Holistic Detective Agency" by Douglas Adams.
Relevant evidence: Yes