At first, Alexa Glock's initial case as a traveling forensic investigator seems straightforward—her expertise in teeth helps her identify the skeletal remains of a hunter found on the remote Stewart Island of New Zealand. But when she realizes the bullet lodged in his skull was not self-inflicted, and then a second shark-ravaged body washes up on Ringaringa Beach, it's clear that something dangerous is lurking in the beautiful waters surrounding the island.The disturbing sight seems to confirm what locals have hashed out in the pub: shark cage-diving, lucrative for owners and popular with tourists, has changed the great white sharks' behavior, turning them into man-eaters. Tensions between cagers and locals mount as Alexa dives into the harrowing case. While measuring bite patterns, she makes a shocking discovery that just might lead her to who—or what—is behind both deaths.