Lupin's leaving was on the last Friday of June.
He packed in the morning — Ron knew because he passed the Defence classroom on the way to breakfast and saw the door open and Lupin inside, moving around the room with the quality of someone who had long experience of leaving places and had developed efficient methods. The room was almost clear already.
Ron stopped in the doorway.
'I will carry this in,' Lupin said, not looking up. He had always known when Ron was there.
'Do you need help?' Ron said.
'No,' Lupin said. 'Thank you.' He folded his teaching notes into a leather case and looked up. 'How are the exam results likely to be?'
'Good,' Ron said. 'The Defence practical I managed well.'
'I noticed,' Lupin said, with the slight dry quality he occasionally had. You were clearly holding something back and I was not sure whether to mark you up for control or down for incomplete demonstration.'
'Which did you do?' Ron said.
'Up,' Lupin said. 'The control itself was impressive.' He closed the leather case. 'You'll have a new Defence teacher in September.'
'Yes,' Ron said.
'I hope,' Lupin said, 'that whoever it is gives you something worth learning.'
'The most useful thing I learned this year was from you,' Ron said. 'The message casting. And the Patronus theory before the form arrived.'
Lupin looked at him.
'The principle of it,' Ron said. 'That the memory needs to be certain rather than happy. That the difference matters. I've been applying that principle to other things all year.'
'I hope it continues to be useful,' Lupin said.
'It will be,' Ron said.
They stood in the nearly empty classroom and Ron felt, as he occasionally did, that a moment was ending something that had been good.
'The business,' Ron said. 'Have you and Sirius —'
'We've been talking,' Lupin said. 'Since March. Sirius has a location in mind. Diagon Alley, toward the quieter end.' A pause. 'He's been researching bookshops with the thoroughness he used to apply to Quidditch tactics.'
'Harry wants to invest,' Ron said. 'I said I'd mention it.'
'Sirius already told him he could,' Lupin said. 'Harry apparently said he wanted his name on something real that he'd built with people he trusted.'
'Good,' Ron said.
'Take care of yourself in Uganda,' Lupin said.
'I will,' Ron said.
'And take care of Harry,' he said. 'Not by managing things. Just by being there.'
'I know the difference,' Ron said.
'I know you do,' Lupin said. 'That's why I said it to you rather than about you.'
Ron left him to his packing and walked down the corridor toward breakfast, carrying the thing Lupin had just given him carefully.