The Hall cleared slowly.
Not reluctantly — not with the quality of people who didn't want to leave — but in the specific unhurried way of people who had been somewhere good and were letting the leaving have its proper time. The students filtered out in twos and threes, most of them talking in the focused quiet manner of people who were still processing what they had watched. Hannah Abbott left with Neville, her hand briefly on his arm in the way that communicated something she had decided not to say directly, which was the right communication for the moment. Cedric left with Justin, the two of them in the specific conversation of people who had both lost matches and were comparing what they had learned from losing them.
Harry was last, standing near the Hall doors with the quality he had after sessions that had pushed him somewhere new — the quality of someone who was between versions of themselves, the old one not yet fully gone, the new one not yet fully arrived. He looked at Ron across the clearing Hall with the expression of someone who had understood that tomorrow, watch was not a deflection.
'Go to the common room,' Ron said. 'Tell the others.'
Harry went.
The Hall was empty.
Or almost empty. McGonagall had not left. She was standing at the northern end where the three professors had stood during the matches, and Flitwick was beside her with the barely-contained quality of someone who had been waiting for this since the first conversation about it, and Snape was three feet to her left with the controlled stillness that was simply his mode of occupying space.
Ron walked to the center of the Hall.
The cleared floor had the specific quality it had after the tournament — the absence of people who had recently filled it, the particular warmth of a space that had been used for something genuine and still held the residue of it. He stood in the center and felt the space with the full awareness he usually kept in the background and brought forward for specific occasions. The hall's dimensions. The ceiling at the height it always was. The ward perimeter he had set that morning still faintly present in the stone, not active but there, the way work stayed in a space after it was done.
He looked at the three of them.
'I want to be clear about the conditions,' he said. 'No limits on casting. No holding back for the sake of the setting. If I've been wrong about what I'm capable of, I'd rather find out now and in here than in June.'
McGonagall looked at him with the expression that had been arriving across five years and had, by now, fully formed. 'You haven't been wrong,' she said. Not warmly — McGonagall's warmth was always the precision of someone who only said accurate things. 'About anything, to my knowledge.'
'The conditions suit me,' Flitwick said, with the quality of someone who was entirely in the right place at the right time and knew it.
Snape said nothing. He had his wand in his hand.
Ron drew his.
'Begin when you're ready,' he said.
McGonagall moved first.
It was not the move of someone who was uncertain about the arrangement or needed time to settle into it. It was the move of someone who had assessed the situation and had decided that the specific advantage of the first cast belonged to whoever was willing to commit to it, and had committed. The Transfiguration sequence she opened with was not the teaching variety — it was the combat application, the specific version of Transfiguration that turned the environment against you, floor and air and available matter becoming things that required management at the same moment as the casts themselves.
He met it with the field binding.
Not the full version — not the four-minute sustained output version he had shown Dumbledore in September. The compressed version, deployed in a ring six feet in diameter around him, that dampened the environmental Transfiguration at the floor level while leaving his own casting entirely unaffected. It went up in the same second McGonagall's sequence arrived, which was not a coincidence but the specific result of having been thinking about how to manage McGonagall's combat approach since August.
Flitwick, on his right, was already moving.
The Charms came fast and threaded — the dueling champion's technique, the same thing he had shown Harry with the tempo control and the elegant minimum — and they came from the angle that his field boundary was designed for and from the angle it was not, simultaneously, because Flitwick had spent seven minutes watching Harry navigate his approach and had drawn conclusions. The conclusions were correct. Flitwick had identified that the field compressed rather than extended and had aimed two casts at the field's boundary edge.
He let those two casts through.
Not because he had to — he could have extended the field, though it would have cost duration — but because letting them through gave him the information of where Flitwick was aiming from, which was information he needed, and because the two casts that came through the boundary were Charms he could redirect. He redirected them at the floor, harmless, and the movement cost him nothing meaningful.
Snape had not moved.
This was not caution. Ron had been tracking Snape's position from the first second with the divided attention that the three-way engagement required, and Snape's stillness was not the stillness of someone waiting to find their moment. It was the stillness of someone who was watching him manage McGonagall and Flitwick simultaneously and was building a picture of everything he was doing — the field, the redirects, the position, the specific way his attention moved between two active threats — and was going to use the picture.
He gave Snape less time to finish it.
He dropped the field.
The move was unexpected because dropping an active working mid-engagement was not a standard dueling choice — it surrendered the defensive advantage the field represented. What it gave him was the specific mobility that the field had been costing him: he had been standing in place for twelve seconds while managing the incoming from two directions, and standing in place against Snape was the specific thing he could not afford to do.
He moved left, fast, cutting across the line between McGonagall and Flitwick so that they were no longer on flanking angles but behind him — briefly, not a sustainable position, but enough to reorient the geometry of the engagement.
Snape cast at where he had been.
The cast was precise and fast and would have been effective from a Legilimency standpoint as well as a spell standpoint — it had the quality of something that was also an attempt to read, to get through the Occlumency compression and find the decision-making in progress. He met it with the closed-room quality he had used in the corridor in October, the surface that gave nothing away, and the cast landed on the closed surface and slid off it and he was already repositioning.
McGonagall adjusted to his new position.
What followed was three minutes of the most demanding magic Ron had done outside the Tuesday sessions with Dumbledore.
The three-way engagement had a specific quality that no two-person duel produced: the requirement of simultaneous full attention in multiple directions, the constant management of angles that kept shifting because all three of them were moving, the specific cost of maintaining offensive output while managing two separate defensive demands. He had been thinking about this problem since August, which was when he had understood that the faculty duel was going to be three-way and had begun designing for it. The design was not a plan — plans broke on contact with three skilled opponents who had their own intentions — but a set of principles. First: never let a fixed position last more than four seconds. Second: use the geometry of the three-way engagement so that any two opponents were occasionally in each other's line of cast. Third: the field was for specific moments of high incoming, not a sustained defence.
The field came up and down three times in the three minutes. Each time it came up he was at the edge of a high-incoming sequence and needed the three seconds of compressed space to generate a response; each time it came down he used the mobility it released to change the geometry.
Flitwick adapted to the field's intermittence faster than McGonagall, which was consistent with Flitwick's style — he was the quickest adapter in the room and had been since the first exchange. By the end of the second minute he had mapped the pattern of when the field came up and had started aiming his casts for the window just before it, the half-second of reinstating it where Ron's attention was partially occupied with the reinstating.
He caught two of those casts on a Shielding Charm and let them slow him half a step.
Snape used the half step.
The Binding Jinx that came from Snape in the first second of the third minute was the most sophisticated piece of spell work Ron had encountered outside Dumbledore's sessions — not the standard version but a modified one, the modification making it conditional rather than direct, designed to activate on the second full step after it landed rather than immediately, which meant it would activate precisely when he was repositioning and his weight was moving forward. He saw the modification in the cast — he could read spell work at the structural level in the way that years of Arithmancy-grounded Occlumency produced — and he had approximately three quarters of a second to decide what to do about it.
He took a full step forward.
Not the second full step — the first one, deliberately. He stopped on the first step with his weight forward and let the Jinx's timer read the position and wait, and in the half second that the Jinx was waiting he sent a Disarming Charm at Snape's wand from the angle that the half-step had opened.
Snape's wand did not leave his hand. He had a Shield up before the Charm arrived, which meant he had anticipated that Ron would find and use the half second rather than avoid it. What the Shield produced was not a deflection but a lock — the Charm absorbed into it, the Shield using the Charm's energy to reinforce itself — which was the specific advanced Shield technique that Dumbledore had described in a Tuesday session as one of Snape's signatures.
Ron released the Jinx.
He simply didn't take the second step. He went right instead, off the Jinx's tracking, and the Jinx expired without activating, and Snape's Shield was one absorbed Charm heavier than it had been, which was a cost.
Everything was a cost in a three-way engagement. The question was whose costs were accumulating faster.
McGonagall's Transfiguration sequences had been finding smaller and smaller gaps as the three minutes progressed — she was not faster or more powerful than she had been at the start, but she had been building a map across three minutes with the patient thoroughness of someone for whom map-building was a core skill, and the map was nearly complete. When it was complete, she would be able to route her casts through the specific gaps it described with the efficiency that had ended Susan's match in five minutes, and he needed to prevent the map from finishing.
He interrupted it.
Not by attacking McGonagall directly — that was the predictable move and she had been defending against it since the first exchange. He interrupted it by doing something that was not an attack: a sustained Illumination Charm, full output, deployed not at anyone but at the Hall ceiling, flooding the space with light that was three times the intensity of the enchanted candles, the specific quality of a sudden brightness that required a fractional recalibration from anyone who had been operating in the Hall's ordinary light.
The recalibration was genuine but small — half a second, perhaps, from each of them.
He used all three half-seconds.
Three casts, simultaneously directed — the specific multidirectional casting he had been developing since the field binding work in fourth year, the output splitting across three vectors rather than concentrated on one. Not Disarming Charms — those required more precision in the wand movement than simultaneous casting allowed. Tripping Jinxes, targeted at the wand hand of each, the specific version that created momentary proprioceptive disruption rather than physical force.
McGonagall deflected hers on reflex.
Flitwick redirected his with a Charm that converted the Jinx's energy into forward momentum, stepping into it rather than away from it, which was either the correct tactical move or simply the dueling champion's instinct and was probably both.
Snape's Jinx landed.
His wand hand disrupted for approximately three quarters of a second — not long, not damaging, but sufficient. In those three quarters of a second, Snape's next cast had a different wand angle than he had intended, and the modified Binding Jinx that followed did not go where it had been aimed.
Ron was in the position the Jinx had been aimed at.
He was not there because he had moved — he was there because he had not moved, because he had read where Snape was aiming and had decided that staying was better than moving, and because the disrupted angle meant the Jinx arrived six inches to his left rather than at his wrist.
The Jinx passed him.
He sent the Disarming Charm at Snape from the position he had not moved from, with the flat certainty of someone who had been building toward this cast since the third minute.
Snape's wand left his hand.
The Hall was not silent. There was no one in it to be silent. But the quality of the space changed — the specific quality of a room in which something significant had just happened, present in the air and in the stone even without witnesses.
Snape looked at his empty hand. He looked at Ron. His expression was the same unreadable thing it was in all the significant moments Ron had observed it — not readable in the usual way, but present with something that the surface managed without fully concealing.
'Retrievo,' Ron said, and Snape's wand returned to his hand.
McGonagall and Flitwick were both still, which was the appropriate response to the outcome of a casting sequence they had both been part of and which had concluded in a way that neither of them had been certain would be possible from the first conversation about it.
McGonagall was the first to speak.
'The Illumination Charm,' she said. Her voice had the quality of someone identifying a mechanism. 'You used it to generate simultaneous disruption. Not as an attack — as a creation of simultaneous window.'
'Yes,' he said.
'The simultaneous casting,' she said. 'Three vectors. You've been developing that since—'
'Fourth year,' he said.
She was quiet for a moment. 'And the decision not to move, on the last cast.'
'Snape's wand angle was disrupted six inches left,' he said. 'Moving right would have put me in the Jinx's path. Moving left would have taken me out of the effective Disarming range. Staying was the only position where both outcomes were available.'
Snape looked at him. He had the expression he had had in the corridor in October — the expression of a Legilimens who had performed a habitual assessment and received a non-routine result. But it was something more than that now. It was the expression of someone who had seen the full picture and was sitting with it.
'The principle Dumbledore taught you,' Snape said, with the flat quality of statement rather than question. 'From Grindelwald's duelling theory. Closing the gap between power and application.'
'Yes,' Ron said.
Snape was quiet for three seconds. Then: 'It is,' he said, 'adequate preparation for what you are preparing for.'
From Snape, this was the thing it was.
Flitwick, who had been watching the conversation with the quality of someone who wanted to say several things and was determining which ones were appropriate to the moment, said: 'The multidirectional casting — I want the theoretical framework for it. At some point when you have the time.' He paused. 'I know you're busy. Whenever.'
'After June,' Ron said.
'After June,' Flitwick agreed.
McGonagall looked at Ron for a long moment with the expression that had been building across five years. It was not warm in the performed sense. It was the warmth of total accuracy — the expression of someone who had been watching a process complete itself and was receiving the completion without requiring it to be anything other than what it was.
She said: 'Good.'
She said it in the tone that good meant when McGonagall said it and meant it fully, which was to say it was not a small word.
Ron lowered his wand.
The Hall had the quality it had at the end of something worth the time — the specific warmth of a space that had been used for its proper purpose. Outside the high windows the February afternoon was doing its late work, the light going golden at the angle it went at four o'clock.
He thought about June. About the shape of it. About what the Tuesday sessions and the ward work and the rituals and the five years of building had been building toward, which was arriving now in its final form and which he could feel in the quality of the magic still settling in the Hall's air.
He was ready.
He had been ready for a while.
He put his wand in his pocket and walked out of the Hall and went to find the others.