Scooby followed, hopping up to plant his forepaws on the desk and lowering his head to sniff at the letters.  The very thought that these were written by someone intending harm to one of his pack brought a soft growl from the Great Dane, even as he shifted his stance (accidentally leaning into Velma, which might push her into Daphne) to make sure he could reach from one end of the scattered papers to the other.