Dirk Gently's Holistic Detective Agency

The genesis of the novel was in two Doctor Who serials written by Adams, City of Death (in which an alien tries to change history at the cost of erasing humanity from existence) and in particular the cancelled serial Shada, which first introduces a Cambridge professor called Chronotis who is hundreds of years old. He has been living and working at a Cambridge college for centuries, apparently attracting no attention (noting with appreciation that the porters are very discreet). In Shada, Chronotis's longevity is due to him being a Time Lord, and his time machine is an early model TARDIS. These trademark elements from Doctor Who were removed by Adams for Dirk Gently. Shada was cancelled before completion due to a production strike and later released on VHS with Tom Baker narrating the unfilmed segments. The story was also animated in 2017 and released on DVD.[1]

A number of elements in the novel were inspired by Adams' time at university. For example, one plot thread involves moving a sofa which is irreversibly stuck on the staircase to Richard MacDuff's apartment; according to his simulations, not only is it impossible to remove it, but there is no way for it to have got into that position in the first place. In a similar incident that occurred while Douglas Adams attended St John's College, Cambridge, furniture was placed in the rooms overlooking the river in Third Court while the staircases were being refurbished. When the staircases were completed, it was discovered that the sofas could no longer be removed from the rooms, and the sofas remained in those rooms for several decades.

The South Bank Show revealed that Adams based Chronotis' rooms on the rooms he occupied in his third year at university. Likewise, Richard's room – filled with Macintosh computers and synthesisers – was based on Adams' own flat (visited and photographed by Hi-Fi Choice Magazine). The piece of music by Bach that is heard aboard the satellite is "Ach bleib bei uns, Herr Jesu Christ" from the cantata "Bleib bei uns, denn es will Abend werden", BWV 6 (also an organ chorale BWV 649). Adams stated that this was his personal "absolutely perfect" piece of music, and that he listened to it "over and over; drove my wife completely insane" while writing Dirk Gently's Holistic Detective Agency.[2]

Richard MacDuff attends the Coleridge dinner at his old college St Cedd's, where he witnesses his former tutor, Professor Urban "Reg" Chronotis, perform an inexplicable magic trick in which he makes a salt cellar disappear, then reveals it by smashing a centuries-old clay pot that a young girl brought to the dinner. The dinner concludes with a reading of Coleridge's poem "Kubla Khan", including a mysterious (and fictional) second part.

Meanwhile, an Electric Monk and his horse find a mysterious door on an alien planet, which leads them to Earth. MacDuff and Prof. Chronotis find the horse in the Professor's bathroom, but this does not seem to overly surprise him. The Monk, misunderstanding a casual comment, shoots and kills MacDuff's boss Gordon Way. Way's ghost makes several attempts to contact the living.

MacDuff returns to his London flat and engages in odd behaviour, including climbing a drainpipe to break into the flat belonging to his girlfriend, Susan Way, to erase an embarrassing message left on her answering machine. Susan returns from a night out with Michael Wenton-Weakes. Wenton-Weakes subsequently begins behaving strangely, becoming obsessed with Coleridge and intense feelings of aggrievement.

The next day, MacDuff visits former schoolmate Dirk Gently, a self-claimed "Holistic Detective" who believes in the "fundamental interconnectedness of all things" and is currently searching for a missing cat. Gently informs MacDuff that he is a suspect in the death of Gordon Way, and begins to unravel the mysterious chain of events. Gently concludes that MacDuff had been possessed by a ghost and that a time machine was involved. Ultimately, the two travel to St. Cedd's to meet with Prof. Chronotis, and a complex history is revealed.

Four billion years in Earth's past, a group of aliens called Salaxalans landed on Earth; however, a mistake caused by their engineer – who used an Electric Monk to irrationally believe the proposed fix would work – caused their landing craft to explode, killing the Salaxalans. The ghost of the Salaxalan engineer roamed the earth, watching human life develop, searching for a way to undo its mistake, and waiting to find a sympathetic soul that it could possess. In the early 19th century, the ghost possessed Coleridge, and influenced his writing of "Kubla Khan" and "The Rime of the Ancient Mariner", but found the poet too 'relaxed' on laudanum to be useful. It discovered that Prof. Chronotis possesses a time machine disguised as his rooms at the college. At the aforementioned Coleridge dinner, the ghost influenced Prof. Chronotis to use the time machine to perform the magic trick, using the opportunity to lure the Electric Monk and its horse to Earth. However, the ghost found the Monk unusable for its purposes. The ghost subsequently attempted to possess MacDuff, resulting in his odd behaviour, before finding its sympathetic host in Wenton-Weakes.

The ghost, still in possession of Wenton-Weakes, arrives at Prof. Chronotis' quarters and convinces them to take him back in time to just prior to the explosion of the Salaxalan ship, so that he can make the proper repairs. As they watch the ghost take Wenton-Weakes' body out towards the ship, MacDuff gets a call from Susan and learns that Wenton-Weakes recently killed a professional rival (Susan having been conveyed the information by the ghost of Gordon Way). Gently realises that the similarity between Wenton-Weakes' jealousy toward his rival and the ghost's jealousy of humanity was what allowed the ghost to possess him. Gently concludes that the Salaxalans intended to settle permanently on Earth, and the explosion of their ship was what caused the beginning of life on the planet. In order to foil the ghost's plans, Gently, MacDuff, and Prof. Chronotis travel to the 19th century. Gently interrupts Coleridge, becoming the "man from Porlock" and preventing the full version of "Kubla Khan" from being written.

Upon arrival back in the 20th century, Gently, MacDuff, and Prof. Chronotis find small changes as a result of their actions, including the existence of the works of Johann Sebastian Bach, which had not existed in their original timeline. Gently learns that the missing cat he was searching for never went missing, and sends his client a revised bill that reads, "To: saving human race from total extinction – no charge."

• Dirk Gently (also known by a number of other names, including Svlad Cjelli), the operator of the eponymous detective agency that operates based on the "fundamental interconnectedness of all things." He specialises in missing cats and messy divorces. At university, Dirk, seemingly deliberately, created rumours about having clairvoyant abilities by vigorously denying that he had any. He concocted a "get-rich scheme" offering a university exam preparation service and was eventually sent to prison when, by sheer coincidence, he accurately duplicated the exam papers for that year without having seen them.
• Richard MacDuff, a young software engineer working for WayForward Technologies II, owned by Gordon Way. His Anthem software, which is designed as a spreadsheet, but also has a unique feature to convert corporate accounts into music, was extremely popular, but he is falling behind in his deadlines to create an updated version. Throughout the book, he tries to figure out how a couch became impossibly stuck in the L-shaped stairway to his flat, forcing him and any visitors to climb over it to get to his flat.
• Reg (Professor Urban Chronotis, the Regius Professor of Chronology), Richard's old college tutor, a fellow of St. Cedd's College, Cambridge with no apparent duties, who is "on the older side of completely indeterminate". He has a predisposition for childish conjuring tricks and an extremely bad memory.
• Gordon Way, the owner of WayForward, who is pressuring Richard to complete his behind-schedule software project, and ends up getting shot for no immediately obvious reason a few chapters into the book.
• Susan Way, sister of Gordon Way and professional cellist, and the "specific girl that Richard is not married to".
• An Electric Monk from a planet very far from the Earth. Electric monks are coincidentally humanoid robots designed to practice religion in their owners' stead. This particular monk had accidentally been connected to a video recorder and, in attempting to believe everything on the TV, had malfunctioned and begun to believe "all kinds of things, more or less at random", including things like tables being hermaphrodites and God wanting a lot of money sent to a certain address. Since it was cheaper to replace the Monk than to repair it, the Monk was cast out in the wilderness to believe whatever it liked. The Monk also owns a somewhat cynical horse, which he was allowed to keep because "horses were so cheap to make". Upon his arrival on Earth, the Monk has several humorous misadventures.
• Michael Wenton-Weakes, the spoiled son of wealthy parents, known pejoratively as "Michael Wednesday-Week", which is when he promises to have things done by, such as the next issue of his poorly-managed magazine Fathom. His mother sold Fathom to Gordon Way after his father's accidental death when the latter was changing an electric plug. While Michael seems largely apathetic and yielding to others, the loss of Fathom bothers him much more deeply than anyone realises.
• Samuel Taylor Coleridge, writer, one of the founders of the English Romantic Movement. Also a famous laudanum user. In the novel, he is an alumnus of St. Cedd's College. His poems Kubla Khan and Rime of the Ancient Mariner figure prominently in the plot.
• Johann Sebastian Bach, the composer, does not in fact exist in the novel's universe. At the beginning of the story Susan, a concert cellist, is having problems practising a piece. During the novel Prof. Chronotis uses his time machine to board the Salaxian ship, still in orbit around the Earth. Inside the ship they encounter elaborate and beautiful music that seems to be the result of the ship's computer system operation, similar to Richard's Anthem program. After they have foiled the ghost's plot and destroyed the ship, Richard finds Susan practising the same music he heard aboard the ship. She tells him it is by Bach. Prof. Chronotis later tells Richard how he managed to retrieve some of the music by introducing it in the Baroque period through the invention of a fake composer.

Reviewing the book for The Times, John Nicholson wrote it was "endearingly dotty", but doubted its commercial potential.[3] Austin MacCurtain of the Sunday Times reviewed the paperback edition in 1988, saying that it was "more of the same" as Hitchhiker's, and that the "cosmic romp is stretched thin at times but will not disappoint fans".[4] The book was the 9th highest-selling hardback in the UK in 1987.[5]

J. Michael Caparula reviewed Dirk Gently's Holistic Detective Agency in Space Gamer/Fantasy Gamer No. 84.[6] Caparula commented that "The writing is wry and quite British, and the novel's quirky spirit is reminiscent of Rudy Rucker's mathematical farces. A nice change for Adams, proof that his talent goes far beyond the meandering Hitchhiker saga."[6]

In 1990, the Magill Book Reviews said "The author's whimsical sense of humor and his sense that the universe has many unexplored possibilities will arouse the interest of a wide readership."[7]

This novel caused Adams to become acquainted with the well-known scientist Richard Dawkins. As Dawkins explains, "As soon as I finished it, I turned back to page one and read it straight through again – the only time I have ever done that, and I wrote to tell him so. He replied that he was a fan of my books, and he invited me to his house in London."[8] Adams would later introduce Dawkins to the woman who was to become his third wife, the actress Lalla Ward, best known for playing the character Romana in Doctor Who. One of her early serials on the programme was City of Death, which Adams wrote, and which shares certain plot elements with the novel.

On 5 January 1992, Dirk Gently, Richard MacDuff, Dirk's secretary, and the Electric Monk all appeared in the Douglas Adams episode of the British arts documentary series The South Bank Show.[9] Michael Bywater played Dirk, while Paul Shearer played both Richard and the Monk. Several characters from The Hitchhiker's Guide to the Galaxy were also featured, played by the original television series actors.

The book has been adapted for stage performance as Dirk and in 2005, some fans of Douglas Adams produced an amateur radio series based on the first book. Their efforts began and were coordinated on the Douglas Adams Continuum website.[10] Three episodes were completed.[11] Apart from the radio broadcasts, Douglas Adams recorded both unabridged and abridged readings of the first novel for the audiobook market.

In a thread on the official Message Boards of Douglas Adams' website, when a reader inquired about the specific mechanics of how the ending worked out, Adams responded: "Ahem. All I can say is that it was as clear as day to me when I wrote it and now I can't figure it out myself. Sorry about that. I'm actually thinking about it at the moment as I've been re-reading the book in preparation for doing a screenplay. I've got a little bit of sorting out to do..."[24]

• Dirk Gently's Holistic Detective Agency by Douglas Adams, reviewed by Ted Gioia (Postmodern Mystery)
• Review of BBC Audio Dramatisation of Dirk Gently's Holistic Detective Agency by Douglas Adams, Booklover Book Reviews
• Dirk Gently's Holistic Detective Agency title listing at the Internet Speculative Fiction Database