When a former Russian spy and his daughter were poisoned in the cathedral city of Salisbury, a quiet corner of England became the frontline of an international crisis.

The Salisbury Poisonings: A Spy Next Door reconstructs how Putin's bid to settle an old score with Sergei Skripal exploded into a geopolitical flashpoint, exposing the shadowy conflict between Russia and the West. Blending rare interviews with figures from former Prime Minister Theresa May to MI6 chiefs and KGB agents, archive footage and stylishly constructed recreations, it draws on testimony from across the full spectrum of the crisis. Threaded through it all is investigative journalist Christo Grozev, the man who first pieced together the identity of the culprits. A story of power, revenge and two men's intertwined fates, its aftershocks are still being felt today.

Content guidance: Contains discussion of murder, poisoning and Russian labour camps.