The Calling of the Grave - (David Hunter 4): Harry Treadaway is Dr David Hunter: the darkly compelling new TV series ‘The Chemistry of Death’ – streaming now on Paramount+

When DI Terry Connor turns up on David Hunter's doorstep, it's an unwelcome reminder of the past in more ways than one. The two used to be friends before Connor's behaviour caused a bitter rift. And the news the policeman brings is even less welcome: the psychotic rapist and murderer Jerome Monk has escaped from high security prison.