Twenty-five children in the room, and twenty-three of them folded up cross-legged right where they were standing. Walden seldom used the aura of terror a senior teacher could generate on actual children. Faces turned towards her with big eyes. She knew this group—she tried to know every group, obviously. She’d done the arcane safety carousel with them in Year Seven, and would do it again next year when they hit Year Ten. But two years was a long time, and children could change dramatically in early puberty. The only names she remembered with complete certainty were the class clown, Morris, and a small intense girl who asked excellent questions, whom she’d pegged as a future Invocation student—Noor. Morris was the one she would have expected to be in the middle of the trouble, but he was folded on the floor with the rest of the chastised audience. It was only the two duelists still standing. Walden dragged the name of the gangly boy with the flickering shield out of her memory—Alfie, she was almost sure, though he was a foot and a half taller than when she’d last taught him. Noor, tiny, bespectacled, with a silky dark ponytail, was the one with her hands full of fire. They stood as if they hadn’t heard, focused entirely on each other.

“Alfie, Noor,” began Lilly in a pretty good you’re-in-trouble tone.

“Heads down,” snapped Walden, feeling the stirring of magic in motion a moment before it happened.

Arcane safety lessons paid off: the Year Nines ducked and covered without question as a green sheet of flame erupted over all their heads. The slower on the uptake were grabbed by the quick ones and pushed flat. Walden and Lilly moved in the same moment to rescue Noor’s actual target. Lilly might be an inexperienced teacher but she was a very good evoker, so the shield she flung up on top of Alfie’s panicky, flickering attempt was almost instantaneous, a sheer and shining wall of magical force. Green fire hissed and sizzled against it like boiling water poured into a pan, and then winked out.