The first thing Hermione produced in class when she tried the Patronus was a silver mist that filled the practice room from wall to wall and then dissipated.
Lupin looked at it.
'You've been practicing,' he said
'Since around october, but it still didn't form,' Hermione replied, with the tone she used for her own failures, which was precise and clinical and considerably less patient than the tone she used for anyone else's.
'It will,' Lupin said. 'The power is clearly there. The memory needs anchoring. What were you thinking of?'
She was quiet for a moment. 'My parents. The night they came to pick me up from King's Cross at the end of first year.'
'Hold that thought but go deeper into it,' Lupin said. 'Not the event. The feeling at the centre of the event. What were you certain of, in that moment?'
She thought about this the way she thought about problems she intended to solve, which was with her entire attention.
From the corner Ron watched and did not offer anything, which was the correct approach. Hermione did not need coaching when she was working on a problem. She needed space.
She cast again.
A shape began to form in the silver mist — something small and quick and low to the ground. It lasted approximately four seconds before dissolving, but it had form. There was an animal in it.
Lupin looked at Ron briefly, with the expression of a teacher who had just seen something.
'Again,' he said to Hermione.
She cast a third time.
The silver mist gathered with more intention than the first two attempts, the shape inside it clearer — something low and quick and decisively itself. It ran three full circuits of the room before dissolving, and in those three circuits it had form enough to be unmistakable.
An Otter
Lupin watched it fade. His expression had the quality of someone who had seen something both unexpected and correct.
Ron saw what arrived. He raised his camera and took a photograph, because some things needed to be seen.
Ron did not say what he was thinking, which was that the otter suited her in the specific way that the best Patronus forms suited their casters — not as a symbol of who they were but as an expression of what they were at their most resolved.
He would tell her eventually.
Not tonight.