The two stood a few paces apart, wands drawn, and from their expressions looked as if they were about to duel. Neville Longbottom, as ever projected an odd sense of uncertainty, mixed with a vague air of not quite incompetence.
Opposite him, Zacharias Smith looked ill at the possibility of swapping with Neville. Only Ravenclaw pride kept him there, and ready to show he could cast the spell better than Neville.
Harry and Ron exchanged a tight nod, both willing Neville to get the spell right, first time.
Verto Permuto.
Only Neville's wand lit with magic, despite the incantation, and the gestures Zach's wand didn't light up. The spell failed. Professor Binns floated between the two students before a second attempt could be made.
"Here we see the difficulty of the spell." Professor Binns explained. "We need both casters to be done well, and at the same time, for the swap to happen."
Zacharias' cheeks burned with shame and anger, as the professor talked. Drifting backwards from the pair and back through his lectern, he gestured for them to try again.
Verto Permuto.
This time both wands lit with eldritch magic. The light shooting from the wand tips, instead of crashing together. They danced in a tight sphere of magic between the pair, before continuing on to land on the opposite wand. Both students gave a stiff shudder, and stepped back uncertainly. Raising a hand to their heads, the wide eyed look on both their faces telling everyone present the spell had worked.
"It worked... It worked, Harry." Zacharias' tone was pure Neville Longbottom, sounding surprised at his own success. While opposite, Neville's body looked concerned, and glanced towards some fellow Ravenclaw students for support.
"Well done! Well Done!" Professor Binns looked the most animated he'd ever been seen. "Twenty points to Ravenclaw and Gryffindor."
Harry smiled back at Neville, and Ron added a weak smile in support too.
"Okay, now swap back."
Zacharias already had his wand drawn and was ready to repeat the spell.
"Reversal is the exact same spell as for the initial swap..." the professor said, "and can only be used to restore the parties."
Neville was immediately nervous about repeating the spell, and the possibility of getting it wrong, but...
Verto Permuto.
The spell restored them to their original bodies, as professor Binns invited the club members to experiment in pairs.