Writer Steven Moffat and actress Dolly Wells dissect their devilish new drama starring David Tennant, Stanley Tucci and Lydia West. The series follows the mysterious lives of a prisoner on death row, a vicar and a maths teacher who happens to be trapped in a cellar. Most detective shows are 'whodunits' but this one is more like a ‘who will do it’, or possibly a ‘you've done it’. The details of this thriller have been kept closely under wraps until now so join Steven and Dolly as they go into all the twist and turns of the series while also delving into key moments as the story unravels.