Moon Shadows by Lisanne Harrington

James Manarro wakes up to a strange world in which nothing makes sense. As if it isn’t bad enough that a werewolf has been stalking the town of Wolf Creek and James had to kill it, or that James is dealing with the fact that he is a werewolf too, now the whole world is silent, and everyone—his parents, neighbors, and friends—seems to have disappeared. Then he hears a voice…one he can’t possibly hear because it belongs to his best friend, Riff, who has been dead for over three years, killed by the first werewolf to attack the town. But when James runs out to find Riff, he is plunged into a world of thick white fog filled with monsters determined to kill him once and for all…