[Roy is so frustrated. If he had any more information, he would know who to strike. He believed in Ling's ability to combat demons - so an obvious target would have been whoever the other seer named...

He could kill Kimblee, who had to be a false seer, and would pull for the death of his partner. But if that was taken to be the act of the demons, it could put Ling in even more danger.]

If we had just one more piece of information...