Purity in Death - J. D. Robb Piatkus

We seek only the purity of justice. By the time this message reaches you, the first execution will have taken place.

New York, the summer of 2059, and the unbearable heat drives everyone to the very edge of madness. So when homicide lieutenant Eve Dallas is called to a violent attack by a deranged man, she thinks she's in control. She couldn't be more wrong.

Someone is managing to spread insanity like a virus, forcing targeted criminals to lose their minds. But with a method of execution so unpredictable and brutal that even those behind it are starting to panic, Eve must act decisively.

Faced with a spiders-web of betrayal protecting those responsible, Eve is forced to fight back and fight dirty.