The sirens come to Oaks Consulting with a simple problem: figure out the culprit behind several traps and mischief around Sirenum Island. After weeks of managing her strained partnership with Cord, to Shasta Oaks a job three thousand miles away sounds perfect. Maybe the distance will even improve their relationship.

It doesn't take Shasta long to learn the real reason the sirens want outside help. Their first clutch is about to hatch. They've decided Shasta can solve their mystery and make the island safe again.

If an island of expectant mothers isn't enough of a problem, Cord shows up uninvited, as do trip wires, sharks, and explosions. To protect Cord, to save the clutch, to set the island to rights, Shasta will have to be more than earth born. She'll have to be the bringer of justice... And even that may not be enough.