Harry’s mind had gone blank with shock. The three of them stood transfixed with horror under the Invisibility Cloak. The very last rays of the setting sun were casting a bloody light over the long-shadowed grounds. Then, behind them, they heard a wild howling.

“Hagrid,” Harry muttered. Without thinking about what he was doing, he made to turn back, but both Ron and Hermione seized his arms.

“We can’t,” said Ron, who was paper-white. “He’ll be in worse trouble if they know we’ve been to see him….”

Hermione’s breathing was shallow and uneven.

“How — could — they?” she choked. “How could they?”

“Come on,” said Ron, whose teeth seemed to be chattering.

They set off back toward the castle, walking slowly to keep themselves hidden under the cloak. The light was fading fast now.

By the time they reached open ground, darkness was settling like a spell around them.

“Scabbers, keep still,” Ron hissed, clamping his hand over his chest. The rat was wriggling madly. Ron came to a sudden halt, trying to force Scabbers deeper into his pocket. “What’s the matter with you, You stupid rat? Stay still — OUCH! He bit me!”

“Ron, be quiet!” Hermione whispered urgently. “Fudge’ll be out here in a minute —”

“He won’t — stay — put —”

Scabbers was plainly terrified. He was writhing with all his might, trying to break free of Ron’s grip.

“What’s the matter with him?”

But Harry had just seen — stinking toward them, his body low to the ground, wide yellow eyes glinting eerily in the darkness — Crookshanks. Whether he could see them or was following the sound of Scabbers’s squeaks, Harry couldn’t tell.

“Crookshanks!” Hermione moaned. “No, go away, Crookshanks! Go away!”

But the cat was getting nearer —

“Scabbers — NO!”

Too late — the rat had slipped between Ron’s clutching fingers, hit the ground, and scampered away. In one bound, Crookshanks sprang after him, and before Harry or Hermione could stop him, Ron had thrown the Invisibility Cloak off himself and pelted away into the darkness.

“Ron!” Hermione moaned.

She and Harry looked at each other, then followed at a sprint; it was impossible to run full out under the cloak; they pulled it off and it streamed behind them like a banner as they hurtled after Ron; they could hear his feet thundering along ahead and his shouts at Crookshanks.

“Get away from him — get away — Scabbers, come here —”

There was a loud thud.

“Gotcha! Get off, you stinking cat —”

Harry and Hermione almost fell over Ron; they skidded to a stop right in front of him. He was sprawled on the ground, but Scabbers was back in his pocket; he had both hands held tight over the quivering lump.

“Ron — come on back under the cloak —” Hermione panted. “Dumbledore — the Minister — they’ll be coming back out in a minute —”

But before they could cover themselves again, before they could even catch their breath, they heard the soft pounding of gigantic paws…. Something was bounding toward them, quiet as a shadow — an enormous, pale-eyed, jet-black dog.

Harry reached for his wand, but too late — the dog had made an enormous leap and the front paws hit him on the chest; he keeled over backward in a whirl of hair; he felt its hot breath, saw inch-long teeth -

But the force of its leap had carried it too far; it rolled off him. Dazed, feeling as though his ribs were broken, Harry tried to stand up; he could hear it growling as it skidded around for a new attack.

Ron was on his feet. As the dog sprang back toward them he pushed Harry aside; the dog’s jaws fastened instead around Ron’s outstretched arm. Harry lunged forward, he seized a handful of the brute’s hair, but it was dragging Ron away as easily as though he were a rag doll —

Then, out of nowhere, something hit Harry so hard across the face he was knocked off his feet again. He heard Hermione shriek with pain and fall too.

Harry groped for his wand, blinking blood out of his eyes

“Lumos!” he whispered.

The wandlight showed him the trunk of a thick tree; they had chased Scabbers into the shadow of the Whomping Willow and its branches were creaking as though in a high wind, whipping backward and forward to stop them going nearer.

And there, at the base of the trunk, was the dog, dragging Ron backward into a large gap in the roots — Ron was fighting furiously, but his head and torso were slipping out of sight —

“Ron!” Harry shouted, trying to follow, but a heavy branch whipped lethally through the air and he was forced backward again.

All they could see now was one of Ron’s legs, which he had hooked around a root in an effort to stop the dog from pulling him farther underground — but a horrible crack cut the air like a gunshot; Ron’s leg had broken, and a moment later, his foot vanished from sight.

“Harry — we’ve got to go for help —” Hermione gasped; she was bleeding too; the Willow had cut her across the shoulder.

“No! That thing’s big enough to eat him; we haven’t got time —”

“Harry — we’re never going to get through without help —”

Another branch whipped down at them, twigs clenched like knuckles.

“If that dog can get in, we can,” Harry panted, darting here and there, trying to find a way through the vicious, swishing branches, but he couldn’t get an inch nearer to the tree roots without being in range of the tree’s blows.

“Oh, help, help,” Hermione whispered frantically, dancing uncertainly on the spot, “Please…”

Crookshanks darted forward. He slithered between the battering branches like a snake and placed his front paws upon a knot on the trunk.

Abruptly, as though the tree had been turned to marble, it stopped moving. Not a leaf twitched or shook.

“Crookshanks!” Hermione whispered uncertainly. She now grasped Harry’s arm painfully hard. “How did he know —?”

“He’s friends with that dog,” said Harry grimly. “I’ve seen them together. Come on — and keep your wand out —”

They covered the distance to the trunk in seconds, but before they had reached the gap in the roots, Crookshanks had slid into it with a flick of his bottlebrush tail. Harry went next; he crawled forward, headfirst, and slid down an earthy slope to the bottom of a very low tunnel. Crookshanks was a little way along, his eyes flashing in the light from Harry’s wand. Seconds later, Hermione slithered down beside him.

“Where’s Ron?” she whispered in a terrified voice.

“This way,” said Harry, setting off, bent-backed, after Crookshanks.

“Where does this tunnel come out?” Hermione asked breathlessly from behind him.

“I don’t know…It’s marked on the Marauder’s Map but Fred and George said no one’s ever gotten into it…It goes off the edge of the map, but it looked like it was heading for Hogsmeade…”

They moved as fast as they could, bent almost double; ahead of them, Crookshanks’s tail bobbed in and out of view. On and on went the passage; it felt at least as long as the one to Honeydukes… All Harry could think of was Ron and what the enormous dog might be doing to him…He was drawing breath in sharp, painful gasps, running at a crouch….

And then the tunnel began to rise; moments later it twisted, and Crookshanks had gone. Ahead Harry could see a patch of dim light through a small opening.

He and Hermione paused, gasping for breath, edging forward. Both raised their wands to see what lay beyond.

It was a room, a very disordered, dusty room. Paper was peeling from the walls; there were stains all over the floor; every piece of furniture was broken as though somebody had smashed it. The windows were all boarded up.

Harry glanced at Hermione, who looked very frightened but nodded.

Harry pulled himself out of the hole, staring around. The room was deserted, but a door to their right stood open, leading to a shadowy hallway. Hermione suddenly grabbed Harry’s arm again. Her wide eyes were traveling around the boarded windows.

“Harry,” she whispered, “I think we’re in the Shrieking Shack.”

Harry looked around. His eyes fell on a wooden chair near them. Large chunks had been torn out of it; one of the legs had been ripped off entirely.

“Ghosts didn’t do that,” he said slowly.

At that moment, there was a creak overhead. Something had moved upstairs. Both of them looked up at the ceiling. Hermione’s grip on Harry’s arm was so tight he was losing feeling in his fingers. He raised his eyebrows at her; she nodded again and let go.

Quietly as they could, they crept out into the hall and up the crumbling staircase. Everything was covered in a thick layer of dust except the floor, where a wide shiny stripe had been made by something being dragged upstairs.

They reached the dark landing.

“Nox,” they whispered together, and the lights at the end of their wands went out. Only one door was open. As they crept toward it, they heard movement from behind it; a low moan, and then a deep, loud purring. They exchanged a last look, a last nod.

Wand held tightly before him, Harry kicked the door wide open.

On a magnificent four-poster bed with dusty hangings lay Crookshanks, purring loudly at the sight of them. On the floor beside him, clutching his leg, which stuck out at a strange angle, was Ron.

Harry and Hermione dashed across to him.

“Ron — are you okay?”

“Where’s the dog?”

“Not a dog,” Ron moaned. His teeth were gritted with pain. “Harry, it’s a trap —”

“What —”

“He’s the dog…he’s an Animagus.”

Ron was staring over Harry’s shoulder. Harry wheeled around. With a snap, the man in the shadows closed the door behind them.

A mass of filthy, matted hair hung to his elbows. If eyes hadn’t been shining out of the deep, dark sockets, he might have been a corpse. The waxy skin was stretched so tightly over the bones of his face, it looked like a skull. His yellow teeth were bared in a grin. It was Sirius Black.

“Expelliarmus!” he croaked, pointing Ron’s wand at them.

Harry’s and Hermione’s wands shot out of their hands, high in the air, and Black caught them. Then he took a step closer. His eyes were fixed on Harry.

“I thought you’d come and help your friend,” he said hoarsely.

His voice sounded as though he had long since lost the habit of using it. “Your father would have done the same for me. Brave of you not to run for a teacher. I’m grateful…it will make everything much easier….”