It is a hot Tucson afternoon in May and petty criminal Zeb and his old school pal Robin are casing out a house, about to launch a 'home invasion' and steal money off a drug dealer who's set up shop in this quiet residential street. Zeb doesn't really want to be there, but he's failed at everything else, been chucked out of home and thinks he needs to prove himself to the more worldly-wise Robin. But really he's pretty scared and has a bad feeling about it all . . .

Detective Sarah Burke and the team are called to a mass shooting in a quiet residential street; it looks like a home invasion gone very wrong. There are several dead bodies but the crime scene just doesn't make sense - until one of the 'dead' victims suddenly escapes and another man is seen running from the house.

Once again, as well as juggling her complicated home life, Sarah Burke is faced with a ballistics mystery to find out exactly what went down - and why - in this particularly violent and mysterious crime.