Dozens of identical blue shoes are found in the ocean off the southwestern coast of Florida, all with a severed human foot inside, all exhibiting unmistakable signs of violence. They appear out of nowhere one day, floating in on the tide.

Called off the tarmac from his return flight back to New York City, Pendergast reluctantly arrives on Captiva Island and is quickly drawn into the mystery. A preliminary pathology report indicates the feet were wrenched from their bodies in the crudest of ways. As the days continue, more wash in until the number tops one hundred.

Soon, Pendergast and his partner, junior agent Coldmoon find themselves squaring off against an adversary more powerful and deadly than they've ever encountered.