Butterfly Effect ; H. Potter

17. dementor's kiss.

"One wrong move, Peter," said Lupin threateningly, ahead. His wand was still pointed sideways at Pettigrew's chest.

Silently they tramped through the grounds, the castle lights growing slowly larger. Snape was still drifting weirdly ahead of Sirius, his chin bumping on his chest. And then -

A cloud shifted. There was suddenly dim shadows on the ground. Their party was bathed in moonlight.

Snape collided with Lupin, Pettigrew, and Ron, who had stopped abruptly. Sirius froze. He flung out an arm to make Harry, Antheia, and Hermione stop.

Antheia stared ahead at her father. He had gone rigid. Then his limbs began to shake.

"He didn't take his Potion tonight!" Antheia gasped. "He's not safe -"

"Run," Sirius whispered. "Run! Now!"

Antheia looked sadly at her father who was in tremendous pain. Harry leapt forward but Sirius caught him around the chest and threw him back.

"Leave it to me - RUN!"

There was a terrible snarling noise. Lupin's head was lengthening. So was his body. His shoulders were hunching. Hair was sprouting visibly on his face and hands, which were curling into clawed paws. Crookshanks's fur was on end again, he was backing away -

As the werewolf reared, snapping its long jaws, Sirius disappeared from Harry's side. He had transformed. The enormous, bearlike dog bounded forwards. As the werewolf wrenched itself free of the manacle binding it, the dog seized it about the neck and pulled it backwards, away from Ron and Pettigrew. They were locked, jaw to jaw, claws ripping at each other -

Harry stood, transfixed by the sight; too intent upon the battle to notice anything else. It was Hermione's scream that alerted him -

Pettigrew had dived for Lupin's dropped wand. Ron, unsteady on his bandaged leg, fell. There was a bang, a burst of light - and Ron lay motionless on the ground. Another bang - Crookshanks flew into the air and back to the earth in a heap.

"Expelliarmus!" Harry yelled, pointing his own wand at Pettigrew; Lupin's wand flew high into the air and out of sight. "Stay where you are!" Harry shouted, running forwards.

Too late. Pettigrew had transformed. "Stupefy!" Antheia tried, but she missed Pettigrew by inches. His bald tail whipped through the manacle on Ron's outstretched arm, and he scurried through the grass.

There was a howl and a rumbling growl; Harry turned to see the werewolf taking flight; it was galloping into the Forest -

"Sirius, he's gone, Pettigrew transformed!" Harry yelled.

Sirius was bleeding; there were gashed across his muzzle and back, but at Harry's words he scrambled up again, and in an instant, the sound of his paws was fading to silence as he pounded away across the grounds.

Harry, Antheia, and Hermione dashed over to Ron.

"What did he do to him?" Hermione whispered Ron's eyes were only half-closed; his mouth hung open. He was definitely alive, they could hear him breathing, but he didn't seem to recognize them.

"I don't know."

Harry looked desperately around. Black and Lupin both gone ... they had no one but Snape for company, still hanging, unconscious, in mid-air.

"Let's just take them up to the castle and get some help," suggested Antheia.

But then, out of the darkness, they heard a yelping, a whining; a dog in pain ...

"Sirius," Harry muttered, staring into the darkness.

He had a moment's indecision, but there was nothing they could do for Ron at the moment, and by the sound of it, Black was in trouble -