The deadliest threat in California doesn't come with a warning—it slips into your system, rewires your mind, and turns you into a killer with a smile. When a banker opens fire at Folsom Flea Market, Detective Kat Hastings catches the case—but takes three bullets before she can stop the carnage. Now she's in the ICU, the victim of a drugged-up killer. That night, during a gig, Sonny Marshall watches helplessly as his band's guitarist collapses mid-set, brought down by a drug no one can identify, his body locked in euphoric paralysis. The incident rattles Sonny, but the news about Kat hits harder. When he learns she was among the victims, he drops everything to be at her side. Kat is more than a casualty—she's the woman he loves, and the one person still holding him to the right side of the line. As he begins to connect the dots, a chilling truth emerges: two designer drugs, no less deadly, created by the same phantom chemist. Sonny isn't a cop. He's a blues saxophonist with a bad knee, a worse Oxy habit, and a white knight complex he can't shake. With Kat recovering and chaos spreading, he steps outside the law—guided by a code the courts don't recognize and a team that doesn't ask for forgiveness. As Sonny teeters on the edge, one question haunts him: How do you stop a killer no one can see—without becoming something you don't recognize yourself