The countdown has begun. Who will die next? 

DCI Adam Bishop has never seen anything like it. Five murder victims – all with numbers written above their bodies. And the spray-painted daubs reveal a horrific truth: the killer is counting down…

When Dr Romilly Cole learns of the murders, they trigger memories of a traumatic past she has tried hard to forget. But getting involved with the case is a bad idea. She and Bishop have history – and working together could never end well.

Adam and Romilly soon realise the truth lies in a decades-old case, and only Romilly holds the key. But they must act quickly, because with every passing day, there are more victims. And as the numbers edge toward zero, the murders get closer to home…