"Oh!" caught wholly off-guard; he had more or less given up on anything but a certain level of discomfort around Susan, an expectation that they would never be quite on the same page, and he'd been trying to acclimatize himself to it, to be at peace with the idea of not everyone liking him. He certainly hadn't expected something akin to an apology.

He brushes his surprise aside and smiles at her. "It's my pleasure, truly. I suspect the results will be...quite substantial, as you say."