Nail-biting and terrifying, this film shows us the essential work of Hope Not Hate, a group who use hidden cameras and incredibly treacherous fieldwork to expose the threat of extremism around the world

Some good documentaries feel as if they land in their director’s lap. Icarus, from 2017, seemed to luck out when doping in cycling became an international scandal midway through production; 2022’s Navalny included the Russian government’s brutal targeting of Vladimir Putin’s political rival. Although these were riveting films, there was a sense that they happened to be in the right place at the right time with a camera. In the case of Undercover: Exposing the Far Right, cameras were running during an extremely eventful 10 months for Britain, which climaxed with the race riots this summer, providing a cinematic final act. But Havana Marking’s film isn’t just a good documentary – it’s a great one.

Over 90 minutes, it follows investigators from the organisation Hope Not Hate as they track down far-right extremists. At first, this seems like an unnecessary endeavour: social media feels flooded with the “alt-right” broadcasting their views. The race rioters in Britain – and in the US at Charlottesville, Virginia, in 2017 and the Capitol in 2021 – weren’t exactly trying to conceal themselves. But as it continues, the importance of their work becomes increasingly evident.