Dark Carnival. The Chronicles of Jonathan Crowley, #4

It began with a centuries-old curse, writ in blood. It gave way to the hellish fury of the pack. Now, as night descends on Serenity Falls, the fun really begins... A widow is tortured to death-by the husband she killed. A collection of curious dolls has been discovered with a terrifying secret carved in each. And then, with a whistle that screams like Hell, the circus arrives in town to raise a ruckus.
But the Carnival of the Fantastic is raising more than that. It's raising the dead. No one can save Serenity Falls now-except the stranger known as the Hunter. Only he can protect the innocent from the damned. Because only he can tell them apart.