In the final episode of the series, Dirk Gently and his assistant/partner/assistant-partner (note for potential second series: no more of this lame-as-a-two-legged-giraffe ‘joke’, please) Richard MacDuff try to track down a murderer who’s bumping off the agency’s former clients while simultaneously trying to apprehend a stalker.

Establishing the identity of the latter is fairly easy (it’s Dirk himself, although he prefers the term ‘covert experimenter’, which doesn’t really sound any better) but finding the killer is more of a challenge – particularly considering the Holistic Detective is struggling to fend off psychotic unpaid cleaners, Eastern European mobsters listening to banging Slavic hip hop in a Transit van and the redoubtable Detective Inspector Gilks at the same time.

It’s another intriguing plot, this week from Being Human writer Jamie Mathieson, if not quite as interesting as the first two stories in the series, but it moves the show further away than ever from its roots in Douglas Adams’s novels – and unfortunately, this isn’t really a change for the better.

Gently’s stalking of a wife whose husband has left her for the pool cleaner seems far more in keeping with the original character’s amorality than last week’s hints of allure between the sleuth and an artificial intelligence inside the body of a brain-dead woman living behind a filing cabinet (although put like that, it does sound fairly Hitchhikers-esque), but there can be no justification whatsoever for his apparently genuinely humble gratitude to MacDuff.

‘When a man loses sight of his carpet, he is no longer a man,’ Dirk remarks at one point – but if an enjoyably arrogant detective starts being meek and penitent, he’s no longer an enjoyably arrogant detective. It’s all very well trying to add another layer of emotional depth to the show, but last week’s instalment proved that this simply doesn’t work.

Happily, one thing this episode doesn’t share with its predecessor is its policy on being amusing. It’s not as funny as the first story in the series, but there are some definitely some chuckles. The hoarsely-whispered fish-based confrontation with the man from reformed cons group From Jail to Jesus is excellent; Stephen Mangan’s hair in the flashback to ten years previously is a Vidal Buffoon nightmare of hilarious proportions – he looks like Tom Wopat from The Dukes of Hazzard guest starring in a Bon Jovi video – and Dirk’s sub-Withnail hovel of a home with its handy hole in the floor raised a few giggles, even if the best moments therein are either inferior to the original source material (Adams had his detective starting the day with a cigarette under the duvet rather than a glass of red wine) or done better elsewhere (the ‘option two’ phone gag was a pale imitation of the ‘Inception… no’ scene in Mid-Morning Matters).

Best of all is the laugh-out-loud moment when Dirk and Richard are caught behind a bush by the bloke they’re tailing. ‘We’re fine,’ MacDuff assures the man who might be a murderer. ‘We’re just… dogging.’

It goes some way to assuaging any doubts that this is a comedy drama series with the emphasis on the comic, not a rehash of Jonathan Creek. It’s a case of Gently does it – but only just.

Aired at 9pm on Monday 19th March 2012 on BBC Four.

> Buy the Series 1 DVD on Amazon.

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