The gesture towards the stool was as much of an invitation as he was going to get, and Ford was grateful for it. He moved the stool out from the table, though he had no real desire to sit. He leaned one arm against it instead and watched Noble out of the corner of his eye, trying to gauge his mood. Whatever his brother was thinking, though, he had to get on with his questions. Ford doubted that Noble would allow him to just loiter here without speaking for long; he might think Ford had somehow gotten it into his head to come down here to supervise.

"I wanted to ask you a potions question," he admitted a little reluctantly. "Can you tell from the ingredients what sort of thing a potion would do?"