Compare River Marked (Mercy Thompson Series #6)

Being a different breed of shapeshifter—a walker—Mercy can see ghosts, but the spirit of her long-gone father has never visited her. Until now. An evil is stirring in the depths of the Columbia River—and innocent people are dying. As other walkers make their presence known to Mercy, she must reconnect with her heritage to exorcise the world of the legend known as the river devil.