Brisance - The shattering effect of a high explosive
Draco stood helplessly, watching Potter and his friends, the precious diadem clutched close to their chests, weave away from him through the piles of rubbish. He was exhausted; he couldn't give chase. But he daren't lose his prize now.
"Do something!" he shrieked.
To his delight, Crabbe waved his wand. A second later, giant roaring flames leaped high, devouring the heaps of objects around them. Draco smirked. Let Potter outrun that.
Suddenly, the fire twisted. It went round behind them.
Draco found a strength he hadn't known he had.
"Run!" he screamed, lunging forward, desperate to save his own skin.