
But Cas’s own power also has a history, one she can’t remember―or control. One that’s creeping into her mind and fracturing her sanity…just when she’s gotten herself on the hit list of every crime lord on the West Coast. And her best, only, sociopathic friend. Cas won’t be able to save the world. She might not even be able to save herself.

Cas Russell is good at math. Scary good. The vector calculus blazing through her head lets her smash through armed men twice her size and dodge every bullet in a gunfight, and she’ll take any job for the right price.