Fierce, frightening, twisted and addictive.

The Twenty grips you by the throat and keeps on squeezing until the very end.'Chris Whitaker, author of We Begin at the End'So dark you almost have to look away yet so compelling you can't stop turning the next page'Tim Glister, author of Red CoronaThe countdown has begun. Who will die next?A shocking crime scene...DCI Adam Bishop has never seen anything like it. Five murder victims - all with numbers written above.

And the spray-painted daubs reveal a horrific truth: the killer is counting down...A case that twists and turns...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.A race against time to stop a killer...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...