It wasn't until the wolf's shoulder stiffened that Neil noticed the subtle colour difference that had crawled up its leg and was now converging over the timberwolf's entire body. Strangely, Neil's first thought was of the three trolls in the Hobbit movie. Why would it change now if it was allergic to the sun? Perhaps there was something in his blood? But if that was the case, wouldn't the change start from the wolf's muzzle? It was clear whatever had caused the wolf's legs and body to lock up started from its feet. 