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).

Shada was cancelled before completion due to a production strike and later released on VHS with Tom Baker narrating the unfilmed segments.

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.

Likewise, Richard's room – filled with Macintosh computers and synthesisers – was based on Adams' own flat (visited and photographed by Hi-Fi Choice Magazine).

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.

In Cambridge, computer programmer Richard MacDuff has arrived from London to visit his old college, the fictional St. Cedd's, at the invitation of his undergraduate tutor Urban "Reg" Chronotis.

Over a dinner being held in honour of Samuel Taylor Coleridge, Richard explains how he came to work for Gordon Way, who also happens to be his girlfriend Susan's brother.

They also listen to a reading of Coleridge's Kubla Khan, and the narration makes reference to the poem's "second, and altogether stranger part".

While driving to his country home and leaving an extended message on Susan's answering machine, Gordon is shot by a shadowy figure hiding in the trunk of his car.

The caller is a man Richard knew at Cambridge as the eccentric Dirk Cjelli, now using the surname Gently to avoid troubles with the law.

Michael, the son of a wealthy publishing magnate, was unceremoniously terminated from his position as editor of the magazine Fathom following his father's death; he is bitterly resentful of his successor, Alistair Ross.

Dirk then informs his friend that Gordon is dead under mysterious circumstances, and persuades Richard to be hypnotized and describe the events of his evening.

Dirk is particularly concerned about the magic trick, which is, so far as he can tell, utterly impossible, as well as Richard's highly uncharacteristic decision to break into Susan's flat.

His flat is in fact a craft of extraordinary power which can travel through space and time – though, for some reason, it cannot function when Reg's telephone is working, and vice versa.

He is possessed by the ghost of an alien engineer, whose crew had left their own war-torn planet in search of another world on which to build a utopia based around the creation of music.

The engineer finally succeeded with Michael, who is implied to be sympathetic to the ghost's goals due to his fondness for Coleridge's poetry, particularly the second half of Kubla Khan.

Gordon realizes that he will only be able to end his ghosthood if he completes his unfinished business – namely, leaving a message on Susan's answering machine – but struggles to muster the emotional energy he needs to lift a phone's receiver and dial the number.

Galvanized by this discovery, he uses the touch-tone phone in Dirk's office to call his sister, records an answering machine message telling her of the crime, and hangs up, which enables him to "[fall] back to his own rest and vanish".

After Michael, using scuba gear, has walked into the poisonous atmosphere of pre-organic Earth, Richard receives a phone call from Susan.

To stop the engineer from preventing the accident, without which life on Earth could not begin, Richard, Reg, and Dirk travel to Somerset in 1797.

Richard discovers Susan playing a cello piece that is hauntingly reminiscent of the Salaxalans' harmonies and is baffled when she tells him it was composed by someone called "Bach".

"[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.

Announced on 26 January 2007, BBC Radio 4 commissioned Above the Title Productions to make eighteen 30-minute adaptations of Douglas Adams' Dirk Gently books (including The Long Dark Tea-Time of the Soul and the unfinished The Salmon of Doubt), running in three series of six episodes.

[12] The first series began on 3 October 2007 and features Harry Enfield as Dirk, Billy Boyd as Richard, Olivia Colman as Janice, Jim Carter as Gilks, Andrew Sachs as Reg, Felicity Montagu as Susan, Robert Duncan as Gordon, Toby Longworth as the Monk, Michael Fenton Stevens as Michael, Andrew Secombe, Jon Glover, Jeffrey Holland, Wayne Forester and Tamsin Heatley.

[16] There are a number of structural and detail differences between the radio adaptation and the book, mostly to aid the comprehension of the story when split into six half-hour episodes.

Ed Victor, a literary agent who represents Adams' estate, announced that a television adaptation of Dirk Gently's Holistic Detective Agency was in production.