The Patronus came on Thursday of the second week.
He had been working toward it since October with Lupin, in the sessions that had gradually moved from theory to practice to the specific problem of finding the memory that would hold. Lupin had said in December that the form was present — large, low-shouldered — but not resolved. He had been trying different memories since then with the systematic attention of someone who understood that the right memory was not necessarily the most dramatic one but the most certain one: the kind that had no doubt in it.
He had tried the summer. He had tried Egypt — the roof at sunset, which was genuinely one of the best things he had experienced in this body in this life. He had tried Christmas at the Burrow, which was warm and real but had something slightly complex in it that the spell registered.
On Thursday evening in the warded practice room with Lupin, he tried something different.
He thought about Wednesday morning in the common room. Seven minutes of early light and Hermione saying yes with the quality of someone who had already decided and was confirming it. Not a dramatic memory. Not a significant moment by most measures. Just a true one, with nothing complicated in it, nothing that needed qualifying.
He cast.
The Patronus came out fully formed.
It was a wolf. Grey, large, low to the ground, moving with the specific quality of something that knew what it was and where it was going. It circled the practice room once with the unhurried ease of something that was not performing and was simply itself, and then stood in front of him and looked at him with the silver eyes of a spell that had arrived where it was supposed to be.
Lupin was very still.
'A wolf,' Lupin said, after a moment. His voice had a quality Ron had not heard from him before.
'Yes,' Ron said.
Lupin looked at the Patronus for a long moment. Then he looked at Ron. His expression was the expression of someone who had been given information he was going to need time with.
'That's a significant form,' Lupin said.
'I know,' Ron said.
He let the spell fade. The wolf dissolved into silver mist, and the room went back to its ordinary darkness.
They were both quiet for a moment.
'The memory,' Lupin said. Not asking. The tone of a teacher who had been watching someone reach for something for months and was now asking about the thing that had finally worked.
'Someone said yes,' Ron said.'Simply. Without complication.'
Lupin looked at him. 'That's all?'
'It was completely certain,' Ron said. 'That's what you said it needed to be.'
Lupin was quiet again, with the quality of someone who had said that, yes, and was now reconsidering the implications of having been right.
'Can I ask you something?' Ron said.
'Yes,' Lupin said.
'Message casting,' Ron said. 'Using the Patronus to carry a message. I know it's possible. I'd like to learn it.'
Lupin looked at him with the expression he used when Ron produced a request that was several steps ahead of where a third-year student was supposed to be and he had decided to proceed anyway.
'That's advanced Ministry-level communication magic,' Lupin said.
'I know,' Ron said. 'I'd still like to learn it.'
Lupin was quiet for a moment. Then he said: 'We'll begin next session.'
He told Hermione about the Patronus on Friday.
Not about the memory — that was his — but about the form and the message casting. They were in the library, the corner table that had become theirs in the specific way of tables that two people use consistently enough that other people stop sitting there. She was working on a Charms essay. He had the warding theory text open but had not been reading it.
'A wolf,' she said, when he told her.
'Grey,' he said. 'Large.'
She looked at him with the assessing quality she brought to new information. 'That's not a common form.'
'No,' he agreed.
'Wolves are —' she paused, selecting. 'Pack animals. Loyal. Protective. Highly intelligent. Good instincts.' She looked at him. 'That's accurate.'
'You're describing me like a reference book,' he said.
'I'm describing you accurately,' she said. 'Which is what a reference book does when it's correct.' She paused. 'Message casting. That's an advanced version of an already significantly advanced spell. '
'Yes,' he said.
She looked at him for a moment with the expression that was her model updating.
'You're preparing for something,' she said.
'Several things,' he said. 'Not immediately.'
She looked at him for a moment longer. Then she made the decision she often made with him, which was to accept what he had given her and trust the rest was coming, and went back to her essay.
Under the table her foot was next to his. Neither of them moved.
He went back to the warding theory and found he could read it perfectly well.