With two days left to go in the term, Harry had only his Care of Magical Creatures examination remaining on his schedule. Harry was confident that he would perform well on the exam—Hagrid's class had kept Harry's interest for the entire year, mostly because Hagrid's creatures were dangerous if not handled properly. As a result, Harry did not feel the need to study during his last free evening. Instead, Harry had gone down to the quidditch pitch to have one last flight on his Firebolt before the summer holiday. Tomorrow night would be the leaving feast, and the morning afterward Harry would be leaving for London on the Hogwarts Express.

Harry brought his flight to an end as the sun began to set. Although the quidditch pitch was still considered a safe zone, he didn't want to be caught outside in the dark. Chancing an encounter with Sirius Black was bad enough, let alone a dementor.

Harry tucked his Firebolt in the Slytherin equipment shed and closed the door behind him. He would retrieve the broom tomorrow afternoon, just before the feast, and would pack it away for the summer tomorrow night.

As Harry walked back to the castle, he heard a boy's voice, distantly shouting. Shouting was not unusual at Hogwarts; students were constantly jinxing on another, or mis-casting spells, or falling prey to the pranks of the Weasley twins. This voice sounded familiar, though. Harry couldn't place it, until he heard a woman's voice screaming for help. It was Hermione Granger; the first voice had belonged to Ron Weasley.

Harry broke into a run. If Granger was in trouble, he was going to help.

As Harry sprinted up the path, the Whomping Willow came into view. Granger was standing out of reach of its branches, screaming for anybody to help. At the base of the tree was Ron Weasley, being dragged backwards by an enormous black dog. The Grim. By the time Harry reached the tree, Weasley and the dog had disappeared into the hole at the base of the Whomping Willow.

"What happened?" Harry asked, as he reached Hermione's side.

"I don't know!" Hermione said. "That dog attacked us for no reason, and I can't get past the Whomping Willow to help!"

"I'll try," Harry said. Harry darted in, trying to dodge the Whomping Willow's branches. The tree lashed about quickly, striking Harry squarely in his stomach and throwing him back several feet.

"Harry!"

"It's okay," Harry said. He stood and grabbed his ribs, wincing. "It's faster than I thought." Harry took a moment, watching the rhythm of the willow's motions, then darted in again. As the tree brought its branches around, Harry pulled up short. The branches swept past, and Harry sprinted for the hole. As he neared the opening, he tripped on a root and fell square on his face. He heard the Whomping Willow creaking and cracking as it brought its branches around. Harry pulled himself up, using the trunk of the tree for support. As he grabbed at the knots on the tree trunk, one of them pushed into the willow, causing Harry to lose his balance.

Harry had taken too long, he was sure of it. He prepared himself to be whomped. At any moment, the branch would come crashing across his shoulders, and he would suffer the same fate as his Nimbus 2001.

Harry felt a light tapping on his shoulder. He turned and found Hermione standing behind him.

"The willow stopped," she said. "I think you did something. Hit a trigger, maybe?"

Harry looked back at the willow. "Was it this knot?" Harry pushed the knot again, and the willow began thrashing about. "Whoops! Get inside!" Harry grabbed Hermione and dragged her into the hole, just as the willow's branches swept past. The two fell into a heap inside the tree.

"Thanks for the rescue, Harry," Hermione said breathlessly. "Now, would you please get your knee off my kidney?"

Harry and Hermione stood. They were in some sort of secret passage.

"Any idea what this is?" Hermione asked.

"It's a secret passage," Harry said. "It leads to Hogsmeade, somewhere."

"And how do you know that?"

"Sources," Harry said. "Good ones. But they never figured out how to get past the willow…"

"Ronald must be up ahead," Hermione said, drawing her wand. "Let's go."

"You know, now that we're inside the tree with the crazy dog, this doesn't seem like such a good idea."

"Harry, that dog just attacked our friend."

"You're not the one who has been chased by a giant black dog all year! I saw it before school started, and barely escaped on the Knight Bus. Then again at the Gryffindor/Slytherin quidditch match when the dementors attacked. Trelawny has been seeing the Grim in my future all year, and I just saw it in a crystal ball during my exam!"

"Trelawney's barmy," Hermione said.

"Yes, well… I'm just suggesting that maybe we should go get a professor."

"Go, if you want. I'm going after Ronald." Hermione turned and began walking down the passage.

"Why are Gryffindors always saying things like that to me?" Harry muttered. Shaking his head, he jogged to catch up to Hermione.

"By the way," Hermione asked, once Harry had reached her side, "How did you get here so quickly from Hagrid's?"

"Huh?"

"I just saw you at Hagrid's. How did you make it here so quickly?"

"I wasn't at Hagrid's," Harry said, perplexed. "I was over by the quidditch pitch."

Hermione furrowed her brow in confusion. "Hmm."

The tunnel was long and winding. Harry and Hermione moved quickly, but cautiously, prepared for an attack at any moment. No attack came, however, and the two students soon reached the end of the tunnel. There was a ladder leading upward, and a closed trap door.

"Up, I suppose?" Harry asked.

"Of course."

Hermione began climbing, but Harry placed a hand on her shoulder. "Let me go first," Harry said.

"Harry, I'm a perfectly capable witch-"

"I know. Emphasis on 'witch.' If you go first, I can't climb the ladder without looking up your skirt."

"Oh." Hermione blushed. "You first, then."

"I mean, if that's what you wanted, I won't complain…"

Hermione hit Harry on the arm. "Now is not the time!"

Harry seized the ladder and began climbing. When he emerged from the trap door, he turned and helped Hermione climb out.

"Where are we?" Hermione asked.
"I think we're in the Shrieking Shack," Harry said. The building was in complete disrepair. Furniture was tossed about and broken. Ratty curtains hung in front of boarded-up windows. Cobwebs hung from every surface.

"Let's find Ron and get out of here," Harry said. Hermione nodded.

Harry and Hermione went from room to room, wands out, looking for Ron. They found him in the back room, lying on an old, gray mattress. His leg was obviously broken. Ron's face was greenish-white, and he was desperately clutching his rat to his chest. At the foot of the bed was Hermione's cat, stalking back and forth and staring constantly at Ron's rat.

Something was familiar. It itched at the back of Harry's mind. He looked again at the scene before him. Something was missing…

Ron's words from last year shot through Harry's consciousness like a lightning bolt: Where's Lockhart?

Harry dove forward and tucked himself into a roll. Behind him, a gravelly voice spoke: "Expelliarmus!"

Harry heard Hermione yell as her wand was jerked from her hand. Harry's roll had carried him behind a chest of drawers, and there was a dull thud as the spell meant for Harry struck the front of the old piece of furniture. Harry took two deep breaths, leaning for the briefest moment against the back of the chest, causing the cheap particle board to crack and groan. Harry gathered his courage, then stood. "Expelliarmus!"

Harry watched as his spell shot toward a tall wizard with dark, ratty hair—a man who could only be Sirius Black. Black's clothes were in tatters, but they hung on his gaunt body as if they were two sizes too large. His eye gleamed maniacally as he batted Harry's charm away with Ron's wand.

Black fired back at Harry with his own expelliarmus, and Harry ducked back behind the chest of drawers, allowing the spell to pass harmlessly over his head. Harry tried to stand and cast his own disarming charm, but before he could fully rise, Black launched a spell at Harry. Harry was forced to duck behind the chest of drawers once again. Harry tried once more to rise, and once again, Black fired adisarming charm. Harry couldn't get out of a crouch; he was pinned down behind the chest of drawers.

Harry thought through all the curses he knew—diffindo, reducto, incendio, confringo—all of them required a line of sight. But if Harry moved from behind the chest of drawers in order to attack, he would be vulnerable to Black's curses and hexes. There had to be a way to attack Black while still remaining hidden…

Harry was suddenly struck with inspiration. Harry cast three quick cutting curses at the particle board at the back of the chest of drawers, slicing a hole so that he could see into the middle drawer from behind. Harry reached through the hole and pushed the drawer forward with all his might, sending it flying out of the chest and into the room. Through the opening, he saw confusion sweep over Black's face.

"Expelliarmus!"Harry cried. The spell shot out and up, striking Black in the chest under his arm. Ron and Hermione's wands flew into the air, and Harry rose from behind the chest of drawers to catch them neatly. Black held out his arms, palms open and fingers extended.

"Well done, Harry," Black said. "That was impressive."

"Hermione, get over here." Harry spoke without taking his eyes off Sirius Black. When the Gryffindor girl arrived at his side, Harry gave her back her wand.

"Harry-" Black began to speak again, but Harry cut him off.

"Shut up! Don't talk like we're friends! You killed my parents!"

Black nodded slowly. "Yes, but not how you think."

Harry blinked, and it was as if he was seeing the whole world through green water. Everything began to move more slowly. "You think I want specifics? I don't care. I'm going to kill you for what you did."

"You'll regret it, Harry."

"And maybe you'll regret killing my parents."

"I already do. Every day."

"Good." Harry raised his wand, and the green haze seemed to thicken. "Then this will feel even better."

A new voice spoke. "Potter, stop!"

Harry looked to the door of the bedroom. Professor Snape and Professor Lupin stood just inside the door of the room, wands drawn. In Lupin's hand was a crumpled piece of parchment that Harry recognized as the Marauder's Map.

"Snape." Black's voice was mixed with astonishment and hatred. "How did you get here?" Black had backed away from the door and into a corner. His hands pressed up against the walls, and he began casting his gaze from left to right, desperately seeking a way out of the room.

"Step back, Harry," Professor Lupin said gently. "Professor Snape and I will deal with this."

Harry turned back to Black. Harry was so close. So close to justice. Green lightning crackled across Harry's vision, and his body was trembling with fury. He could feel his magic building, as if it were literally pooling in his hands. Harry was ready to lash out at Black. Harry's magic was calling for release. It wanted Harry to kill black, and Harry wanted to do it. All Harry had to do was let it go. Justice was so close…

"Harry, please. Stop." Hermione's voice was soft, and she placed her hand on Harry's right arm. Harry blinked again, and suddenly the world seemed normal. The green was gone. He allowed Hermione to gently push his arm down.

"Thank you, Hermione," said Lupin.

Snape snorted. "Incarcerous." Chains burst out of Snape's wand and bound Sirius Black. Snape strode forward and stood over the escaped convict, smiling triumphantly. "Sirius Black, helpless and under my wand. How long I have dreamed of this day."

"This isn't what you think, Snape," Black said. He began struggling against his chains, thrashing back and forth, shaking his head violently. "Remus, please, you have to listen to me! I didn't betray Lily and James!"

"What could you possibly say to convince me?" Lupin asked quietly.

"Peter is here!" Black screamed. "Look at the boy! The redhead!"

Lupin and Snape exchanged a knowing look. Lupin turned to Ron, who was sitting on the bed, clutching Scabbers desperately to his chest. The rat was twisting in Ron's hands, struggling to break free of Ron's fingers just as violently as Black was struggling against his chains.

"Do you mind if I examine your rat, for a moment?" Lupin asked Ron.

"Scabbers? Why?"

"Because Peter Pettigrew is a rat animagus," Lupin said.

"He is not!" Hermione said confidently. "I looked at the registry after McGonagall showed us her cat transformation. I would have noticed if Pettigrew was there."

"I didn't say he was registered," Lupin said calmly. "Neither Peter nor Sirius nor James registered their ability to transform, but they were all animagi."

"Hermione, I think he's right," Harry said quietly. Harry was standing stock still, frozen in place, staring at Ron and the rat. "Look at Scabbers' front paw. He's missing his smallest toe… and all they ever found of Pettigrew was his little finger…"

Ron pulled his rat closer to his chest. "What are you talking about? Scabbers is just a rat! He's been in my family for ages."

Hermione gasped, and raised her hand to her mouth. "Ron, how old is Scabbers?"

"I dunno." Weasley shrugged. "Percy had him, originally. So… ten or twelve years?"

Lupin held out his hand to Ron. "The rat, if I may?"

Ron shook his head. Scabbers squirmed and wriggled, still trying to escape. It was the most movement that Harry had ever seen out of Ron's rat. "No, it's just Scabbers!"

"Accio rat," Snape said. The rat flew out of Ron's hands, and Snape caught it by its tail, holding it out for all to see. "Here is the rat. Homorphus." A blue light shot out of Snape's wand and struck the rat in the head.

For a moment, nothing happened. Then, Scabbers began to turn and twist and… grow. Snape dropped the rat and took two quick steps backwards. He raised his wand and pointed it at the floor, where Scabbers continued to expand and contort.

Finally, there was a popping noise, and a flash of white light. A short man sat on the floor of the Shrieking Shack. He had a large, pointed nose and buck teeth. His clothes were at least a decade out of date, even by generous wizarding standards. The man glanced around the bedroom with quick, abrupt movements, before finally settling his gaze on Snape.

Snape's voice was soft. "Peter Pettigrew…"

A/N: Just curious: What are your favorite Slytherin Harry stories?

Also, bonus chapter coming up on Tuesday! That's just how the pacing went in the story.