It's every parent's nightmare.

When a high-school shooting leaves dozens dead, including the killers, the grieving community can at least be sure it won't happen again.

But as prosecutor Rachel Knight and detective Bailey Keller dig deeper, they realise that the worst isn't over. The clues at the crime scene don't add up. It seems that the real shooters are still out there...

In the chaos that follows, Rachel and Bailey must scramble to identify the suspects and stop them before they can strike again.

Because the killers have plans. They want to beat their competition.

They want to be the best... at murder.