Since this diagnosis was invented, Stockholm syndrome has become almost a cliche: the psychological disorder making captives feel irrational loyalty and even love for the people holding them prisoner. But why? The victims’ unconscious need to rationalise their own humiliating submission? The brutal power relation of oppressor and oppressed creating its own attachment?

Canadian film-maker Robert Budreau offers his own answers with a fictionalised version of that bizarre event that gave birth to the term – the extraordinary 1973 robbery in Stockholm during which an escaped convict stormed into a bank brandishing a submachine gun, took hostages, demanded his old cellmate be released from jail and brought to his side, and negotiated directly via telephone with Prime Minister Olof Palme himself. His traumatised, mesmerised captives came to believe that this charismatic robber was somehow on their side, against cops and politicians who might sacrifice them to show the world they were tough on crime. (Budreau’s script is based on Daniel Lang’s 1974 New Yorker article.)

Budreau has reinvented the robber, Kaj, as someone with an American background and Ethan Hawke has been cast in the role. (In real life, the Swedish culprit could in fact speak English with an American accent.) Noomi Rapace is the mousy and bespectacled bank teller Bianca who is so intensely thrilled by the life-or-death drama that she starts to fall for her assailant. The film slightly fudges the issue of whether they had sex.

Budreau’s keynote of black comedy depletes the tension and suspense, but this does feel plausible in its stranger-than-fiction chaos, and Budreau interestingly modifies an event from real life: Kaj persuades Bianca secretly to wear a bullet-proof vest so he can fake-shoot her, impressing the police with his ruthlessness. Hawke and Rapace show how this is a sado-masochistic act of love. An absurd or rather absurdist true-crime melodrama.