The Hippopotamus, John Jencks’s second feature film and an adaptation of Stephen Fry’s 1994 novel of the same name, portrays many appearances of various Glenfiddich vintages, an unfortunate horse named Lilac and a truly cringeworthy instance of felatio.

Roger Allam plays Ted Wallace, a misanthropic drama critic and former poet who hasn’t written a poem for over thirty years. After throwing a tantrum during a performance of Titus Andronicus – ‘I haven’t seen so much shit on stage since Copraphilia: The Musical’, he heckles – Ted is fired by his editor and at a convenient loose end. Drowning his sorrows in a pub – the closest this film ever gets to a normal setting – he encounters yogi Jane Swann, the daughter of his ex-girlfriend, who implores Ted to sleuth on her family’s estate following her unexplained recovery from leukaemia. Ted hasn’t visited his best friend Michael Logan’s estate in a decade after a romance with Michael’s sister (Jane’s mother) ended in Ted publicly humiliating her, revealed in a squirm-inducing flashback towards the end of the film. Despite Ted’s reservations, Jane’s offer of £100,000 seems to do the trick. Really, it’s hard to imagine lower stakes.

When he arrives at Swafford Hall, filmed at the Palladian estate West Wycombe Park in Buckinghamshire, Ted finds himself investigating ‘nothing in particular’ amid characters played by a quite frankly bizarre series of casting choices. (Matthew Modine, for some reason, plays a supposedly imposing Thatcherite Lord who instead gapes and flits between accents; the female characters are either ‘f**kable’, ‘plain’ or ‘bat-infested’; Tim McInnerney portrays a particularly troubling caricature of a gay theatre director.) After speaking to each character, Ted realises that the Logan family believe David to be ‘special’ and in possession of miraculous healing abilities. David, an aspiring poet filled with the wonder of nature, is quite happy to accept this.

Thus framed, the unlikely premise of a thoroughly unnecessary film trundles through a listless script with nothing compelling to show for it. It’s pushed along by an excessive amount of voiceover narration, allowing Ted even more c**k-, s**t- and piss-themed one-liners that already dominate proceedings sufficiently (surely an attempt to conserve Fry’s ornate prose for the silver screen). Everything about The Hippopotamus is outdated and has nothing to say about the modern – or indeed any – world, so a meagre attempt to inject contemporary culture in the shape of iPads and Skype as a way for Ted to communicate with Jane feels especially tone deaf.

At first, it appears that Ted is just a hopelessly out of touch, Christopher Hitchens-esque misanthrope who through his haphazard adventure might find meaning and grow up a bit. The story progresses and darkens, from which Ted emerges as hero, despite having no redeeming features whatsoever. In the shrill climactic scene, Ted takes his opportunity to present his case and superiority with the whole Logan family assembled, a la Poirot. In the same scene, rape, bestiality and paedophilia are all shrugged off with alarming ease. The pay-off is non-existent, serving as a platform for Fry’s ham-fisted putting of the boot into religion as the root cause for a warped family’s ill fortune, rather than, for starters, a corrupt class or political system.

The only saving grace of this farce is Roger Allam, who is great, and it’s pleasing to see him in a title role for a change, but that’s about it. Maybe if you imagine it’s a The Thick of It spin-off featuring a less sympathetic Peter Mannion, you could make it through this film, but even then, it probably isn’t worth it.

The Hippopotamus is on general release in the UK, at cinemas, from 2nd June.