Silvery-white light swept across the Quidditch Pitch like a tide. Wherever it passed, even the raging rain seemed to falter. It was Dumbledore's Patronus Charm!
The Patronus Charm required genuine positive emotion to cast. It was even one way to judge whether a wizard was a Dark Wizard.
The Patronus Charm could take a solid form or appear as silvery-white mist. Now silvery-white waves burst from Dumbledore and swept across the entire pitch.
As the ripples brushed gently yet irresistibly over everyone, the icy fear gripping the students melted away, replaced by a wondrous warmth and sense of safety.
The cold flames of anger surging through Will turned at once into cheerful, dancing sparks of joy.
He watched as a hundred or so Dementors met the silvery-white ripples like insects caught in a towering wave. Before that silver surge, they were as fragile as dead leaves.
They let out silent shrieks. Their tattered black bodies seemed to be struck by an invisible giant hand, shriveling as they tumbled far beyond the pitch and vanished into the curtain of rain.
People said Dementors couldn't be killed, but Will doubted they would survive if Dumbledore truly intended to kill them. He had often wondered about it. Boggarts and Dementors were widely said to be "non-beings" that neither aged nor died, but if that were true, sooner or later the world would be overrun with them.
Bathed in silver-white light, the students recovered.
As the light faded and the pitch filled once more with the roar of wind and rain, the students shook off the lingering warmth of the Patronus Charm. Then they realized something grave: Harry Potter, struck by who knew how many Levitation Charms, had been blown away like a kite with a snapped string—or an overinflated balloon. No one knew