8 am: an explosion blasts through a cafe in Central London.
Minutes later, a call from an unknown terror group warns that a far greater attack will be launched in 12 hours' time.
William Garrett, AKA Fox, is awaiting trial for mass murder. He claims he can name the bombers. But only at a price.
THE CLOCK IS TICKING
It's a terrifying race against time for DI Mike Bolt and DC Tina Boyd as they chase their targets across the city in a desperate bid to stop a major atrocity -- before it's too late.