A talented young ghost writer (McGregor) is given what at first looks like a plum assignment – former British Prime Minister Adam Lang ("he wasn’t a politician – he was a craze") needs help with his memoirs, and if the writer can turn the current, unbearably tedious draft into a racy best-seller, a fortune awaits him. There are a few catches: the time frame is tight, many people don’t want him to succeed, and the previous writer assigned to this task has just died in what everyone assures him – not quite convincingly enough – was an accident.

This film is likely to be Polanski’s last, so it’s lucky it showcases everything he does well – perhaps better than any other director alive. In almost every scene it’s either raining, or about to rain, or twilight: it’s at once cosy and menacing. (In Britain the film’s title was simply The Ghost, and although of course we neither see nor expect an actual ghost, one wouldn’t be out of place). McGregor’s character (he is never given a name) badly needs to trust the right people, and not to trust the wrong people – he’s forced into situations where he must make a choice, but he’s never any more sure than we are what the right choice is. The menace builds, the screws tighten with precision, and the ending is wickedly perfect – I guarantee you’ll never forget that final shot.