With their investigation complete, Timmons’ team submit their file to the Crown Prosecution Service, who bring charges for Litvinenko’s murder.

A team of detectives led by Timmons’ ‘best man’ Brian Tarpey arrive in Moscow hoping to interview Lugovoy and Kovtun, now the prime suspects behind Litvinenko’s murder.

Radiation teams swarm across London in a rush to secure potentially contaminated sites visited by the Russian spy.

Detective Inspector Brent Hyatt and Detective Sergeant Chris Hoar are summoned to University College Hospital in London to interview a patient with an extraordinary story to tell.