An unscrupulous political regime barricades itself behind lies, threats and flexed authoritarian muscle to cover up an incident of police brutality. The backdrop to this meticulously detailed thriller from Jan P Matuszyński is Poland 1983, at the ragged, spiteful tail end of communism. But this story, triggered by cops taking the law into their own hands – hands that are clenched into fists – is not as far removed from the present day as it might be. Matuszyński infuses the film with a nervy, volatile energy from the outset, with a snaking, unbroken shot that weaves through the apartment of poet and activist Barbara Sadowska (Sandra Korzeniak). It’s a space in which ideas are exchanged freely, and where Barbara’s son Grzegorz (Mateusz Górski) and his friend Jurek (Tomasz Ziętek) tussle, spirits high after their final school exams. This exuberance spills out on to the streets, where it attracts the attention of militia thugs. The boys are taken into custody and Grzegorz, the more overtly confrontational of the two, is savagely beaten. Jurek’s status, as the only witness to the attack, becomes increasingly precarious. The film is based on a notorious real event, and there is a grim sense of inevitability to the storytelling at times, compounded by the suitably murky colour palette and the overlong running time. But with the help of a couple of outstanding performances from Ziętek and Agnieszka Grochowska, as Jurek’s mother, and its obsessive attention to period detail, the film finally unravels the serpentine coils of corruption.