This adaptation of Stephen Fry's novel leans heavily on the elegant profanity of the source material.

A towering, at times monumentally good central performance from the character actor Roger Allam stands at the heart of The Hippopotamus, but it is entirely alone.

Despite a wonderfully witty voiceover and the bullish playing of a willing ensemble, this bawdy romp consistently stumbles over its more contrived excesses.

Director John Jencks does a great job highlighting the cognitive dissonance resulting from the human race's uneasy blend of practicality and credulity. And Roger Allam is terrific as the self-loathing Ted Wallace, drunk poet turned drunk sleuth.