Dirk Gently's Holistic Detective Agency and The Long Dark Tea-Time of the Soul are the two books written by Douglas Adams (of The Hitchhiker's Guide to the Galaxy fame) starring the character Dirk Gently. A third novel under the working title The Salmon of Doubt was in the works, but its publication was prevented by Adams' death.
Dirk is a small-scale con artist whose latest scheme is working as a "Holistic Detective", who believes in the "fundamental interconnectedness of all things" and how that means that anything might prove useful in solving the whole cases of his clients — which, the way he sees it, means that he can do anything he likes, even take a three-week tropical vacation, and still charge it to the client as an expense. By Finagle's Law, somehow every mundane little job he starts off working on in each novel is somehow actually connected to the main plot, and he's the one who has to solve everything.
Both books were adapted for BBC radio in 2007, starring Harry Enfield as Dirk. A short-lived BBC TV adaptation, Dirk Gently, starred Stephen Mangan. A comic book adaptation published by IDW Publishing was launched in 2015, and a second take at a TV adaptation, entitled Dirk Gently's Holistic Detective Agency, began airing in 2016 and lasted for 18 episodes. Interestingly, the books may or may not share a universe with Doctor Who, as Professor Chronotis, a major player in the first book, actually debuted in the unaired Adams-scripted Doctor Who episode Shada.
This series as a whole provides examples of:
- Bavarian Fire Drill: Dirk's favorite way of getting places he shouldn't be.
- Been There, Shaped History: Prevented Samuel Taylor Coleridge from completing Kubla Kan (coining the phrase "Person From Porlock"), introducing the music of Johann Sebastian Bach, not to mention saving the entire human race from extinction along the way.
- Bilingual Bonus: Dirk's real name, Svlad Cjelli, is similar to how "to master whole" (or "to understand whole", or "to solve whole") would be said in some Slavic languages (e.g. "svladati cijelo" in Croatian)
- Chekhov's Armoury: Dirk isn't wrong—everything that happens in these books is ultimately important. The Dirk Gently books embody this trope really because they are all about the interconnectedness of everything. Chekov's Armoury isn't just a device Adams used, it's what he based the whole book on.
- Contrived Coincidence: Dirk's "holistic" philosophy of detection argues that anything that happens to him or his client is bound to have some relationship to the mystery at hand, no matter how remote the connection. Due to his Laser-Guided Karma (see below), this actually works for him, bringing this trope repeatedly into effect, often to his disgust.
- Hellistics: The title character, a holistic private investigator, is always in the middle of The End of the World as We Know It thanks to a string of ridiculous coincidences; the first book alone involves a crash-landed Ancient Astronaut, a malfunctioning robotic monk, and time travel leading to an old college friend of Dirk's becoming a murder suspect.
- Laser-Guided Karma: Whatever Dirk claims to believe in order to extract cash from gullible people invariably turns out to really be true, but always in such a way that he looks bad, sometimes in such a way that he suffers physical or emotional trauma, and never in such a way that he gets the money.
- Not-So-Phony Psychic: As described above under Laser-Guided Karma; Dirk has twice posed as a psychic, been uncannily right both times, and got arrested for it the first time. He now spends a lot of time insisting to people who were there that he's not psychic. Usually they don't believe him and his reputation from the first incident often precedes him.
- Occult Detective: Given the nature of the setting and his occupation, it was pretty much inevitable that Dirk ends up as one.
- Perpetual Poverty: Dirk never seems to have much money — a Running Gag in Holistic Detective Agency is his secretary quitting over not getting paid — and most certainly never gets paid by his clients. He manages to stay in his office, flat, etc, through arranging the situation so that it would be more inconvenient to actually eject him or force him to pay than just let him be and hope that he'll pay some day.
- Rage Against the Heavens: In response to the Laser-Guided Karma mentioned above, Dirk has also, on at least one occasion, stood outside, fist clenched at the sky, and screamed for life to stop screwing with him.
- Viewers Are Geniuses: The first book in particular depends upon specific knowledge of the works of Samuel Taylor Coleridge in order for its resolution to be even remotely comprehensible, and the books also require a reader to spot small details, some of which aren't always emphasised much or at all, in order to make perfect sense. They do, in fact, make complete sense, but often require several readings for all the details to become comprehensible.
- Year Inside, Hour Outside: Reg and his time machine."I could have sworn you didnít have a beard before you went behind the tree."
Adaptations with their own trope pages include:
- Dirk Gently (BBC TV series, 2010-2012)
- Dirk Gently's Holistic Detective Agency (BBC America/Netflix TV series, 2016-)
Other adaptations of this series provide examples of:
- Shout-Out: The BBC radio adaptions of the novels re-use several sound effects from The Hitchhiker's Guide to the Galaxy (1978), and include a reference to the Sirius Cybernetic Corporation.