Harry raced through the forest, wand held aloft, lumos charm lighting the way. He had long since lost sight of Black—finding a dark-colored dog at night in the Forbidden Forest was nearly impossible—but he could still follow the movement of the dementors. As he ran, Harry made a note to thank Flint for emphasizing physical fitness at quidditch practices. Harry was breathing heavily, but he was nowhere near exhaustion.

Finally, Harry burst through the edge of the trees. He was standing next to the lake at the center of the forest. A hundred yards down the shoreline, the dementors were swarming. At the center of them, Harry could see a large dog spinning in a circle and snapping at their cloaks. As Harry began running toward them, the dog collapsed onto its side, panting heavily. After a moment, the dog shuddered and twisted, and Sirius Black was lying on the sand in human form.

A dementor moved so that its face hovered directly over Black's. Harry was running as fast as he could, but he wasn't close enough. The dementor drew back its hood, and Harry could hear the beginnings of a horrible howling noise. Black's heaving breaths began to slow, slow, slow, until they were almost stopped. The dementor leaned forward.

Harry burst through the circle of dementors. "Expecto patronum!" The silvery wall exploded from his wand. His forward motion pushed the patronus shield directly into the dementor. The creature shrieked and raised its hood, falling back against Harry's assault. Harry spun in a circle, driving the dementors back with his shield.

Harry looked down. "Black, are you okay? Black?"

Black appeared to be breathing, but not much more. Harry suddenly felt the air grow cold. Harry glanced over his shoulder. Dementors were advancing from behind, from the direction of the forest. Harry spun and directed his shield against them. As soon as he did, the air grew cold from the side of the lake. Harry spun again, driving the dementors back over the water.

The creatures were relentless. Harry kept thinking about Ginny Weasley, about the feeling of her heart starting to beat, about how small but happy she looked when she was huddled in her father's arms in Dumbledore's office, about the crushing hug he had received from her mother. He thought of Ginny's desperate embrace when she first awoke, and the burst of happiness in his heart.

Harry's shield grew larger and brighter. The white at the center of the shield was so bright that it was almost painful to look at. The dementors shied away, but continued to swoop around the shore, trying to flank Harry or catch him from behind. And no matter how much happiness Harry held in his heart, he was growing tired.

Harry's shield began to shrink. First a little, then a lot. Lupin hadn't prepared him for this. Lupin had told him that he would only need the shield for a minute, maybe two, and then a professor would intervene. But tonight, deep in the Forbidden Forest, no help was coming. Black was still unconscious at Harry's feet, and the darkness was crushing inward.

Harry's knees buckled. His magic had begun to feed on his physical strength—a last, desperate attempt to power his patronus shield. Harry covered Black's body with his own, holding the shrinking shield above them like an umbrella.

It wasn't enough. As the dementors moved closer, Harry felt the cold of creeping death. Darkness began to seep in at the corner of his vision. He looked across the lake with the last of his strength, refusing to look at the dementors in his last moments, hoping that as he died he would see something beautiful.

At the opposite side of the lake stood a man with a wand. "Expecto Patronum!"

A corporeal patronus burst out of the wand, sweeping across the lake and driving away the crowd of dementors. The light of the patronus glinted brightly off the man's round glasses.

"Dad?" Harry whispered. The patronus swept above Harry, forcing the last of the dementors away. Harry struggled to lift himself, but he had no strength left. He collapsed, and was swept away into darkness.

*!*!*!*!*!*

Harry awoke in the hospital wing, wet and sputtering. Hermione was holding her wand over him.

"Was that necessary?" Harry asked.

"Yes," said Hermione. "Madam Pomfrey wanted to let you sleep, but Dumbledore is coming and we have to speak with him."

The events of the night suddenly flooded to the forefront of Harry's memory. "Wait. How did I get here? Where's Black?"

"Dumbledore and Hagrid found you," said Hermione. "Ron and I were already here with Snape when Hagrid brought you in. He said that Dumbledore took Black to the Astronomy Tower and contacted the Minister of Magic."

"We have to tell them that Black is innocent!" Harry said.

Behind Hermione, the doors of the hospital wing opened, and Dumbledore stepped inside. Before he could say a word, Hermione began to speak.

"Professor! Sirius Black is innocent! You can't kill him! Peter Pettigrew was the Potter's Secret Keeper but he was also the spy and an unregistered rat animagus. He betrayed the Potters and hid as a rat with Ron's family for the last thirteen years but Black caught him tonight and Harry and Ron and I all saw Pettigrew alive but he escaped again! You have to believe me!"

Dumbledore drew his head back and raised his eyebrows. "My, my," he said. "Mr. Potter, can you confirm this?"

Harry nodded. "Everything Hermione said is true. You can ask Professor Snape."

"He's still unconscious," said Hermione.

"Then let's rennervate him!"

"We can't, Harry." Hermione slipped into the lecturing tone she frequently used when she was reciting something she had learned from a reference book. "Professor Snape has a physical injury. Re-enervation is for magical stunning or paralysis. Until the physical injury goes away, re-enervation won't do anything."

"Ron, then," Harry said to Dumbledore. "Ron will tell you."

There was a shout from the other side of the hospital wing. "Roontail Wazlib!" Ron was lying on a bed, his hand thrust into the air with his index finger raised.

"Ron's a mess," said Hermione. "Too many painkilling potions for his leg."

Harry desperately looked back to Dumbledore. "You have to believe us, Professor! Black is innocent."

"I do believe you," Dumbledore said gently. "For you to profess Sirius Black's innocence would take an extraordinary event, the likes of which you have just described. And there is no evidence that you are under any sort of coercive or compulsion enchantment. However…" Dumbledore sighed. "I have already summoned the Minister of Magic. Cornelius Fudge is on his way to Hogwarts at this moment, and he will order that the Dementor's Kiss be performed."

"So we'll tell him that Sirius is innocent!"

Dumbledore shook his head sadly. "Cornelius is a proud man, and Sirius's escape has caused him a tremendous amount of embarrassment. If it became public knowledge that an innocent man had been imprisoned in Azkaban for the last thirteen years, Cornelius would be driven from his office in a matter of days. I am afraid that Cornelius will order the Dementor's Kiss, no matter what the circumstances."

Hermione's jaw dropped. "He'd order an innocent man killed rather than admit a mistake?"

"I cannot be certain, but it is a chance we cannot take," said Dumbledore. "Cornelius will be here soon. We cannot release Sirius from the Astronomy Tower directly—it would be too easy for him to be seen, and Cornelius might use such an occurrence as an excuse to seize absolute control of Hogwarts." Dumbledore smiled sadly. "He is rather paranoid, and imagines that I am plotting to depose him. Ironically, what we do tonight may allow him to keep his job."

"So what do we do?" asked Harry.

"What we need," Dumbledore said, looking at Hermione, "is more time."

"What?" Hermione said. "Oh. OH!" Hermione reached to her neck and began pulling at her necklace. She pulled a small hourglass pendant from underneath her jumper.

"I believe that two turns should do it, Ms. Granger," Dumbledore said, walking toward the doors of the hospital wing. "I am locking you in. Remember, Sirius Black cannot leave through the castle. And please return to the hospital wing by this time, or there may be rather dramatic consequences caused by your apparent apparition."

Hermione nodded. "I understand."

"Good," Dumbledore said. "Best of luck." He moved to close the doors, then poked his head through one last time. "One final thought: I quite enjoyed the walk we took earlier this evening, Ms. Granger. And the password to my office is 'Walnut Whip.' I am sure you will put that information to good use." Dumbledore closed the doors behind him.

Hermione grabbed Harry's wrist. "Hold on tight, Harry."

"What are we doing?"

Hermione turned her pendant over twice. The world around Harry's bed spun and blurred, and Harry felt as if he were being pushed through a cheese grater. With a jerk, everything stopped spinning… except for Harry's head. Harry took a giant, gasping breath of air and raised a hand to his temple.

"It's a time turner," Hermione said, tucking the pendant back under her jumper. "Professor McGonagall gave it to me at the beginning of the year. It's how I've been taking all my classes."

Harry's mind worked quickly, recalling their conversation in the library earlier that year. "How do you find time to sleep? You make time."

Hermione grinned.

"And you think I'm bad with puns," Harry said.

"Yes, well." Hermione glanced around. The hospital wing was empty, and would probably remain so until Hermione and Ron arrived later that night. "It's half past eight. Where are you right now?"

"Er… at the quidditch pitch, I think."

Hermione nodded. "Ron and I are down at Hagrid's. I wanted to review for our Care of Magical Creatures exam, and Ron wanted a snack."

"The three of us are hideously predictable," Harry said.

"Focus, Harry. Time magic is complex and nobody understands it well. Loads of wizards have gotten in trouble by killing their ancestors or themselves."

"So, avoid killing myself? Shouldn't be too hard," Harry said.

"Okay. We need to get Sirius out of the tower, but we can't leave by the front door or we'll be seen. So we'll need to get him out of the window, somehow."

"Why don't we just go to Dumbledore's office and tell him what's about to happen? Then he won't lock Sirius in the tower in the first place."

Hermione shook her head. "That isn't how this works. Sirius is already locked in the tower, so we can't change that."

"No, he isn't," Harry said. "Sirius hasn't even pulled you and Ron under the Whomping Willow yet."

"Just trust me, okay? I've had the Time Turner for a year, and I know how it works. You can't make a direct change to something you know has actually happened. There's something about time magic that prevents you from making those sorts of changes. If you try, then the time magic itself prevents you."

"What do you mean?"

"It's like this. If you tried to run down to Hagrid's right now and stop Ron and me from leaving, you wouldn't make it. You'd trip on the stairs, you'd be given a detention, Peeves would glue you to the floor, something like that. And the closer you get to actually making the change, the worse it gets. If you managed to almost make it to Hagrid's, maybe you'd be attacked by a wild hippogriff that would maul you half to death. But no matter what you did, you wouldn't be able to stop Ron and I from leaving Hagrid's, because Ron and I actually made it to the Whomping Willow and Ron got dragged into the Shrieking Shack."

"So we can't change anything, but we can do other things?" Harry asked.

"That's close enough," Hermione said.

"Okay. So, we know that Sirius gets locked in the tower. We can't leave by the front door, or we'll be seen." Harry put his hand on his chin and scratched thoughtfully. "So we'll need to get him out of the window somehow…"

"I literally just said that," Hermione said snappishly.

"It's probably easiest to fly up there on brooms. We'll just take an extra to Sirius," Harry said.

Hermione's face went white. "Well, one of us could fly up there with a broom," she said. "Perhaps I'll just stay on the ground and make sure that we aren't seen."

"You can't still be afraid of flying," Harry said.

"And what if I am? Besides, you can do it, so there isn't any problem." Hermione began moving toward the door of the hospital wing. "Let's get down to the pitch and steal some brooms."

"Wait!" Harry said. "Professor Lupin has the map."

"What map?" Hermione asked.

"It's called the Marauder's Map." Harry quickly described the map and how it worked. "So, you can see anybody on the Hogwarts grounds, and the map never lies. I saw Professor Lupin holding the map earlier tonight, when he and Professor Snape came into the Shrieking Shack. That's how they knew where to find us."

"And you think Professor Lupin was using the map to keep watch over the grounds?"

Harry nodded. "I bet that Professor Lupin is using it to keep watch on me at the quidditch pitch, in case Black snuck in to attack me. If we go down to the pitch now, Lupin will see two of me, and everything will get screwed up." Harry frowned. "But we can't wait, either, because the doors of the quidditch equipment shed lock automatically at nine o'clock, and we won't be able to get a broom."

Hermione frowned. "That makes things more difficult." She tapped her foot against the ground, deeply lost in thought. "Of course! Hagrid!"

"Hagrid can fly?"
"No, but a hippogriff can! And remember, I saw you at Hagrid's earlier just as Ron and I were leaving!"

"But I wasn't at Hagrid's earlier," Harry said.

"That's the point! I must have seen this future version of you! This is the answer!"

"A hippogriff is not the answer, Hermione. One of them almost gutted Draco earlier this year! Hagrid's my friend, but he has no sense when it comes to appropriate levels of danger."

"I rode Buckbeak earlier this year, and it was fine!" Hermione said.

Harry shook his head. "No hippogriffs, no way. I'm going to do my best to avoid being mauled."

"Well, if we're can't use brooms and we can't use hippogriffs, how do you propose that we get to the top of the astronomy tower?" Hermione folded her arms angrily. "Should we walk? Maybe we could swim!"

Harry thought for a moment, then grinned. "What if we drive?"

A/N: Last week, irdgad asked how the dementors could see Sirius-shouldn't he have disappeared when he transformed? This is a totally legitimate question. Here are my thoughts:

(1) Dementors are blind, but Harry doesn't necessarily know that, or remember it in the heat of the moment.

(2) Dementors have the ability to sense emotions-Sirius says it himself in POA, Ch. 19. He also mentions that animal emotions are less complex than human emotions, and therefore the dementors have a harder time sensing them. Finally, he says that the dementors thought that his animagus transformation meant that he was losing his mind, because his emotions were simpler and less complex.

(3) Now, when Sirius escaped, he used his animagus transformation. He transformed into a dog, and when the dementors brought him food he trotted past. I have always thought it important, however, that Sirius was ALREADY a dog when the dementors arrived. If the dementors had been present to sense/witness his transformation, they would have been able to follow him. It's a pretty easy leap of logic - "Sirius Black was here only a second ago, feeling emotions. Where Sirius Black used to be, there's this strange dog thing, feeling simpler versions of the same emotions. We should probable follow it."

That's what happened here. Sirius was full of fear, which dementors could sense. Sirius transformed into a dog, but was still afraid. The shape of the soul feeling the fear changed, but it's still the same soul. And thus, the dementors follow.