McGonagall's expression when they presented her with the elective changes was the expression of someone who had opinions about impulsiveness and was deciding which of those opinions to lead with.
They were in her office, which had the neat, rigorous atmosphere of a space organized by someone who believed that disorder in the environment produced disorder in the mind. She had their current elective forms in front of her and was looking at the revised versions he'd produced with the specific attention of someone reading them for hidden problems.
"Ancient Runes, Arithmancy, and Care of Magical Creatures," she said. "All three."
"Yes, Professor."
"Ron." She set the forms down and looked at him directly. "You are aware that this represents a significantly more demanding schedule than what the majority of your year will be undertaking."
"Yes."
"And you feel confident that you can manage it?"
"I feel confident that I can try it," he said. "You said yourself that students can switch if it doesn't work out. I'd rather find out by trying than not try."
She looked at him for a long moment. The kind of look that was doing more work than it appeared to be doing.
"The side effects of the memory charm," she said carefully.
"Make things clearer," he confirmed. "I'm not saying I'll be brilliant at all of it. I'm saying I think I can manage the load."
She looked at Harry, who nodded with the steady confidence of someone who had already decided.
She picked up both forms and signed them with the precise, slightly emphatic pen stroke of someone who was reserving the right to say I told you so.
"One year," she said. "If either of you finds it unmanageable —"
"We'll tell you," Harry said.
She looked at him as though this was not the response she'd been conditioned to expect from Harry Potter. "See that you do," she said, and then, before they could stand: "Was there something else?"
He sat back down.
"I wanted to ask about O.W.L.s," he said. "Whether you can sit them for subjects not taken as classes. Privately, through the Ministry."
McGonagall's expression moved through several things quickly. Surprise. Consideration. The specific quality of attention a teacher gave when a student asked something that was either very clever or very misguided and they hadn't yet determined which.
"In principle," she said slowly, "yes. The Ministry administers O.W.L. examinations independently of Hogwarts for a number of subjects. This is largely a provision for home-educated witches and wizards, or for those in professions that require certification in areas outside standard curriculum." She paused. "It is not commonly used by Hogwarts students."
"What subjects?" he asked.
She looked at him steadily. Then she opened her desk drawer and produced a document that had the formatting of an official Ministry publication — dense, thorough, the kind of thing that existed because someone had once needed to codify exactly this question.
"Healing," she read. "Duelling. Magical Languages. Flying. Magical Arts and Music. Magical Theory. Wizarding Law." She set the document down. "These are the subjects for which the Ministry offers independent O.W.L. certification. Healing and Wizarding Law at N.E.W.T. level as well, as they are the foundation qualifications for those professions."
He absorbed this. Stored it in the eidetic memory with the careful organization of something he intended to return to. He thought about the years ahead and the specific competencies they would require, and he thought about Hermione, who was going to want to know every word of what McGonagall had just said.
"Thank you, Professor," he said.
She looked at him for a moment longer. "Ron," she said, in the tone of someone saying something they've decided to say despite being uncertain of the reception. "Whatever has changed — and something has changed, I think we both know that — I hope you'll use it well."
He met her eyes. "That's the plan," he said.