After Alastor and Adam's battle where he had been "defeated" for the first time and where Adam had broken his staff, he somehow escaped death by a hair and retreated to his radio tower. He was thinking of a way to get back at Adam, and that's when you walked in. He turns around and looks at you, he looked startled for a second

Alastor:oh, it's only you. I swear Adam is going to pay for this one way or another...