From Douglas Adams, the legendary author of one of the most beloved science fiction novels of all time, The Hitchhiker's Guide to the Galaxy, comes a wildly inventive novel—in trade paperback for the first time—of ghosts, time travel, and one detective's mission to save humanity from extinction. Quirky and bumbling private investigator Dirk Gently stumbles upon a ghost, millions of years old, wandering the earth and disturbing its people. Dirk soon discovers this phantom yearns for more than a good haunting: it is desperately trying to go back in time to prevent its own death. But this ghost was no ordinary person, and helping it save itself just might change the modern world as we know it. And not in a good way… Endlessly entertaining, Dirk Gently's Holistic Detective Agency proves that, indeed, “few writers have had such an infectious prose style as Adams” (The Observer). As Dirk Gently tries to solve the mysteries of the universe and the human soul, readers will have their own mystery to solve: Where did the time go?