When The Wicker Man was released, an American public­ation described it as a “philosophical soft-core Scottish thriller musical”, which is true – well, true-ish – but hardly grasps the full glory of the film. For that, you need Allan Brown’s reissued guide, which pieces together the “farce in which misfortune piles relentlessly onto misfortune” from the main protagonists’ competing versions of the truth.

‘Pretty Boy’ Bentley had bought Shepperton Studios and needed to put a film into production immediately to pacify the unions. British Lion had one, and so a film set in springtime was filmed in a bitterly cold autumn. Peter Shaffer drew heavily on Frazer’s Golden Bough for his tale of a priggish policeman sent to Summerisle to investigate the disappearance of a child. He discovers that the islanders have returned to the “old gods” and are planning to sacrifice him to save the apple harvest.

The chapter summaries (“In which a poor fucker receives a man-to-man cuddle”, “In which we relate the saga of Britt Eckland’s stunt arse”) give a flavour of the pleasures on every page. Edward Woodward read his final lines from giant cue cards on the surrounding cliffs. The cast sucked ice cubes so their breath would not show on camera and froze in front of trees adorned with fake blossom. Large amounts of alcohol fuelled endless squabbles.

Despite this, and the fact that its title has become shorthand for bucolic bonkers (“he’s gone Wicker Man”), the film is very disturbing. The book, though, is a witty tribute to a great British horror movie.