Blood Moon (Silver Moon, #3)

Now that Candra and Ben have successfully entered the sixteenth century and left Alaric in the future, it's up to them to stop Ulric and Daciana's banishment to the Otherworld. But there's more to this secretive past than they thought; they not only have to find the wolf that bit their ancestors, but also deal with the town witch, who has the original power to destroy them all.