Wicked Little Letters review – a deliciously sweary poison-pen mystery

Before X or Twitter or even YouTube, if you wanted to vent your rage at an unjust world on a blameless bystander you had to go to the trouble of actually writing a letter and posting it. These were the days of the poison pen letter, an early 20th-century socio-criminal phenomenon here revived by comedian Jonny Sweet’s gleefully sweary script and a competent ensemble of British comedy’s finest directed by Thea Sharrock.

Swearwords, you see, can be very funny – especially when primly pronounced by a pious spinster such as Edith (Olivia Colman), who seems to be the letter writer’s primary target. Or when spurting forth from a potty-mouthed slattern such as Edith’s neighbour Rose (Jessie Buckley), on whom suspicion immediately falls. And these swearwords are particularly funny – a collection of naughty non sequiturs and rococo rantings that derive from the real letters of the Littlehampton libels, a forgotten scandal that terrorised this small Sussex town in the early 1920s. “Piss-country whore”? “Foxy-assed rabbit-fucker”? Epithets this fruity are clearly beyond the wit of man to invent. (And there’s your first clue to the letter writer’s identity.)

Related: Olivia Colman and Jessie Buckley: ‘Never repress a woman – because it will come out’

Some credit should therefore go to Christopher Hilliard, author of the well-researched 2017 book that brought the case back to public notice. It’s Sweet’s script, though, that successfully folds the true crime tale into an eminently exportable period-drama package. And it’s the cast – notably Anjana Vasan as the county’s lone female police officer and Timothy Spall as Edith’s domineering father – who allow for deeper exploration of the underlying motives for such aberrant behaviour. Swearing can be comic, but it might also be the way that a highly pressurised, repressive and patriarchal postwar society lets off a bit of steam.