If he had his suspicions before, those calcified when he saw that drop of the head. Dogs did that, dogs and, sometimes, mistreated men. But there weren't coincidences. He had been forced to believe impossible and untrue things a hundred thousand times over. He could believe difficult things that were true. He had room in his worldview for them, cracked and levered open.
Matt was tall, but shorter than Rory by a an inch or two, not that it seemed to trouble him. He could hide many things under the cover of a reclusive, useful veterinarian, but the carefully maintained bulk of a physical machine was not one of them. He wasn't often the tallest man in the room, but that wasn't usually a requirement.
Let's not make a thing of it. He didn't quite react with surprise, but he did step back halfway, still looking, still holding the knife, deciding.
"Stay," he said, and stepped around the surprise man in the blanket. Halfway into the next room, unafraid, it seemed, to put his back to him, he added, "Clothes."
He didn't drop the knife.
A minute or so later, from the next room, came an almost complete sentence.