Though it was most probably someone one of the now numerous enemies of House Frey that had snuck in and poisoned them, pinning the blame on the extinct House Stark. In truth, it mattered little, the name of House Frey was now forever tarnished and every member of the House would have to look behind their back for all the numerous enemies they had made. And without Old Walder, his foolish descendants had started slaughtering each other over the Lordship.