Strange things happen in the swamps at night. Simply terrible. It all started with an ominous howl. Then they found a rabbit in the yard, torn into pieces... Everyone began to suspect Grady's dog, named Wolf. After all, the dog looks like a real wolf. And he feels at home in the swamps. And sometimes he behaves like a wild animal. And he appeared from nowhere. But Grady knows that the Wolf is an ordinary dog. And dogs don't howl at the moon. And they don’t hide in the wilderness at midnight. And they don’t turn into wild and bloodthirsty monsters on the full moon. Or do they still transform?