This luridly compelling doc unravels the story of Thomas Quick, aka Sture Bergwall, who until recently was considered Sweden’s most notorious serial killer. Viewers au fait with Swedish crime history will be aware why he no longer holds that title, but those who come to the story fresh have a chance to follow a condensed version of the case that, like a fictional detective narrative, reveals a big twist.

Bergwall himself is interviewed throughout, while an actor (Oskar Thunberg) plays him in reconstructions, and it’s to the film’s credit that, even before the revelation, he’s shown to be a deeply troubled human being, not some psychotic scarecrow of evil. The key takeaway point is that serial killers are created, sometimes in ways we don’t expect or understand.

Ultimately, this is far more damning of Bergwall’s doctors, and the police and courts, than of him, while our obsession with serial killers, at its peak in the 1990s, post-Silence of the Lambs and American Psycho, shares some of the blame.