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 "Samuel Barnett (actor)"): On 29 March 2016 it was announced that he had been cast as Dirk Gently in the BBC America adaptation of the "Dirk Gently's Holistic Detective Agency" book series by Douglas Adams.
Relevant evidence: No