Yonie Watereye lives in the bayou. The water there is full of guile, a power that changes people and objects. Yonie, 16, makes a living investigating objects affected by guile, but in fact it's her talking cat, LaRue, who has the power to see guile.

Yonie becomes aware that someone is sending harmful guile-changed objects to certain people, including herself. Her investigation becomes entwined with her hunt for the secrets of her mother's past and leads her to discover dangers hidden within her own family.

In the suspenseful adventure that follows, Yonie and her furry sidekick face challenges that could end their adventuring forever.