An almighty twist and a demented finale rescue the Shaun of the Dead actor’s cartoonish homage to folk horrors – but co-star Aisling Bea deserves better

The trouble with Nick Frost’s knowingly cartoonish and silly comedy paying homage to folk horrors such as The Wicker Man and Midsommar is that Frost has done this kind of movie before, and better. His hugely enjoyable collaborations with Simon Pegg and Edgar Wright, Shaun of the Dead and The World’s End, had a perfect command of comedy horror. The tone here feels less good natured, more self-congratulatory, the comedy not quite so light on its feet. Though it comes into its own with a cheerfully gruesome gorefest in the last half-hour.

Frost writes and stars alongside Aisling Bea (who really does deserve a better horror film). They play Richard and Susan Smith, an ordinary-seeming middle-aged couple with the irritating habit of calling...