It was absolutely silent. Harry and the others crept down the long black-tiled corridor towards the round room of doors at the entrance of the Department of Mysteries.

It had actually taken them a few hours to arrive, because they’d quickly realized they needed to prepare properly. If there were a bunch of house elves down there trying to steal Time Turners, the wizards would need backup. They’d called Luna, since she was developing a real knack for dealing with magical creatures, and she’d insisted on bringing her mentor Silvanus Kettleburn (he was, she said, a world-renowned expert on house elves), even though he himself had been struck squib and, because of his various missing limbs, could only move about with Luna’s assistance. Kettleburn could no longer Apparate himself, so Luna asked Hagrid to bring him on a thestral; and that took quite some time. It was then decided that Hagrid should come along too (or more accurately, he refused to be left behind), and he had to be brought up to speed on everything. Then, when they had all been checked in and issued badges and assembled in the main hall of the Ministry, they (the six humans and six of Hermione’s HELF) had taken ten minutes or so to agree on a plan of assault. In the end there was really only one reasonable way to proceed: to take the elevator to the ninth level and enter the Time Room as quickly and quietly as possible, taking the house elves by surprise. Any other plan would be too dangerous or would alert the elves (if there were any down there) to their presence too soon.

Even this plan was insanely dangerous, and most likely any house elves down there would know they were coming very soon. Not only were house elves ridiculously powerful beings, but with Time Turners, who knows what they could do?

“The first thing to do,” said Kettleburn, “is to order them to give up.”

“Will that work?” asked Harry.

Kettleburn shrugged. “It’s worth a try. House elves, as you know, are extremely loyal. Whatever orders they have from Her — whoever She is — might be overwhelmed by the sight of six wizards ordering them to stand down.”

“What if it doesn’t work?”

Kettleburn smiled wryly. “Let’s just hope that it works.”

“Why are Time Turners kept down here under lock and key?” Harry whispered to Hermione as they quietly tiptoed down the passage. (That is, they were all quiet except for Hagrid, who was shuffling uncomfortably in the tight corridor and occasionally loudly whispering “Sorry! Excuse me!” when he bumped into someone, and Kettleburn, whose homemade prosthetic limbs made unfortunate clicking and clanking noises as he walked, leaning heavily on Luna.) “They can’t be that dangerous. You were allowed to have one back in school.”

“Actually,” said Hermione, “that was a mistake. Remember, they were only invented about fifteen years ago. It wasn’t realized how powerful they were, or how much magic they used. Shortly after we had our little… adventure with Buckbeak, the Ministry found out more about them and decided they should be locked away forever. They won’t make any more.”

“They’re that powerful, huh?” said Harry.

“Yes. And they just get more magical. Every time one is used, the amount of magic they store doubles. No one really knows why.”

“Maybe that’s why Voldemort never tried to get one,” said Harry. “He was afraid if he had that much magic he’d be detected.”

Hermione shook her head. “When he was in charge of the Ministry, he didn’t really care about being detected,” she said. “I don’t think anyone knows why he didn’t use them. Maybe he knew something about them that we don’t.”

They arrived at the black room of spinning doors. Hermione called them all close together into a huddle.

“Ok,” she whispered. “Hopefully no one will be there. Or maybe they’ve already all been stolen.”

“We know Gormenghast’s elves stole one,” said Ron. “They’re probably all long gone.”

“Maybe,” said Kettleburn. “But from what I know about house elves, it wouldn’t be typical for them all to be planning some big operation and working together. Probably small groups of them, from the households of other wizards, are independently trying to destroy powerful magical items.”

“Or maybe Gormenghast’s elves are the only ones who thought of it,” said Luna.

“That’s not likely,” said Ron darkly. “It certainly seemed like Kreacher thought of it.”

“And you folks,” said Hermione, frowning at Kreacher and the other members of HELF, “are being awfully unhelpful.”

“We’re terribly sorry, Mistress Granger,” said one house elf. “We will help you in any way we can, with all our hearts, unless it goes against Her orders.”

“Whoever She is,” muttered Ron.

“Good,” said Hermione. “Because if there are other house elves in there, and they won’t give up quietly, we might need you to save our lives. …Are you ready?”

“Yes, Mistress Granger,” the house elves answered with their bright, eager voices, all in unison. Harry thought he had never been so creeped out by anything in his life.

“Then what are we waiting for!” cried Ron, and he jabbed his wand at the doors. “Apere Chronus!” he cried, and one of the doors on their left popped open.

“Wait, Ron, no!” cried Hermione.

A blast of blue-white light erupted from the door, hitting them all with concussive force. It was as if the air went solid and slammed into them. Harry caught a glimpse of half a dozen house elves inside the Time Room — completely normal-looking house elves, not Gormanghast’s weird half-goblins, with their hands up towards them — and he went sprawling on the slick polished black floor.

He struggled to get to his feet, but before he could properly stand, the house elves hit them with another air blast. He gave up trying to stand, and just rolled onto his stomach. That would have given him a good view of the elves in the Time Room, except that Hagrid, who had not fallen, was shouting incoherently and shaking his fists, right in his line of vision.

“Hagrid!” shouted Harry. “Move!”

He meant for Hagrid to just move out of the way, but Hagrid had other ideas. “Right you are, Harry,” he said, and lumbered forward toward the elves, hands outstretched.

“Watch out, Hagrid!” cried Hermione.

Harry couldn’t see much — Hagrid’s bulk was still blocking everything — but he saw the huge man silhouetted against a blaze of greenish light, and Hagrid staggered, stumbled, and fell.

Fortunately, somehow, he fell forward, straight through the door to the Time Room, where there were half a dozen house elves there to break his fall. There was a shuddering crash, a sound of snapping, smashing wood, high-pitched squeals of house elves and four thunderous claps, and then silence.

Harry finally managed to stand up. “Hagrid! Hagrid!” he cried. “Are you ok?”

Hagrid moaned. “Oh boy,” he said. From somewhere under him came other moans, much more high-pitched. “I’m fine,” he said. “Ow, what did they hit me with? Some kind of headache spell?”

The wizards rushed forward into the Time Room, Luna supporting Kettleburn. As Harry remembered from his last time here, it was filled with diamond-sparkling light, and its walls and bookcases were filled with clocks of every shape and description. The ticking of the clocks rattled in their ears. Two things were conspicuously missing: the glass-fronted case of Time Turners, and the crystal bell jar of Time. Hagrid had fallen on a table and smashed it, and under him were two house elves, struggling feebly under his weight.

“Hold them tight, Hagrid,” said Hermione, as he sat up. “Then they won’t be able to Apparate away without taking you with them, and I’m guessing they won’t want to do that.”

“Where are the Time Turners?” asked Ron.

“There,” said Hermione grimly, pointing with her wand. At the far end of the room was something new: a huge refrigerator-sized black safe, its door covered with a dozen different locks, bolts and fasteners of every description. The door was open, and inside were six small, innocent-looking Time Turners.

“Where’s the seventh?” said Hermione. “There should be seven!”

“Look at Hagrid!” cried Ron.

Hagrid had one house elf in each huge hand. One struggled limply, seeming half-dazed. The other, however, was desperately knocking its two scrawny hands together, as if trying to smash something in its palm.

“Stupefy!” cried Hermione, and her blast caused the house elf to immediately go limp. From its fingers fell a Time Turner, tumbling towards the floor. Harry and Ron both dove to try and catch it. Harry’s outstretched palm was right in place for him to clasp it — it was much easier than catching a Snitch, after all — but then Ron crashed into him, and they rolled together over and over on the floor and up against the wall.

“Dammit, Ron!” shouted Harry. He struggled to his feet. “What has gotten into you?”

“What’s gotten into me?” cried Ron. “You’re the one acting crazy! You’re either rushing around getting in everyone’s way, or you’re just standing there like a dope when you should be doing something!”

“I had that Time Turner, Ron,” said Harry. “I was just about to catch it, and you knocked me away. And why on earth did you open the door to this room before we were ready? What was that crazy stunt about?”

“It was me who was about to catch it!” said Ron. “But you’re too busy thinking about what you’re doing to pay attention to anyone else — “

“Ron! Harry!” said Hermione. “Stop it! We’ve got more important problems! Where has Kettleburn gone?”

Harry looked around desperately. There was no sign of him.

“Kettleburn?” asked Ron. “Kettleburn who?”

“Silvanus Kettleburn!” said Luna. “The world-famous Magizoologist! He was right here!”

“Wait,” said Hermione. “Was he? Now I seem to remember he wasn’t…”

“I definitely remember him,” said Harry, but then suddenly doubted himself. He did remember seeing Kettleburn there — in fact he could remember it quite vividly, at least at first… but the more he probed his memory, the more it seemed to slip away, as if he were only a dream. The memories faded faster than he could grab hold of them.

They all stood there, silently trying to remember.

“I don’t know,” said Harry at last. “Now all I can remember is that I did remember him, a moment ago. But I don’t even think I know what he looks like anymore.”

“The past was changed,” whispered Kreacher. “Changed it was, yes. When the Time Turner was destroyed.”

“What?” whispered Hermione.

“The witch didn’t know,” muttered Kreacher to himself. “She didn’t know. They didn’t tell her.”

“Very secretive,” said another elf, nodding. “The Ministry. Very secretive.”

“Explain this,” demanded Hermione. “When a Time Turner is destroyed, the past changes?”

“They are very dangerous,” said Kreacher. “Kreacher will explain. The Time Turner lets you change the past, but only as long as that Time Turner exists. If it is destroyed, the past changes back.”

Harry’s skin began to crawl. He didn’t know where Kreacher’s explanation was going, but he felt like it could not be good.

“It is like a river, yes?” said Kreacher. “Time is a river. The Time Turner puts a rock in the river, changes the river’s flow. The river goes somewhere new. And then, if the Time Turner is destroyed, the river goes back to its old flow.”

“Oh my god,” said Hermione. Her face was frozen in horrified shock. She sat down heavily, staring straight ahead.

“But that would mean…” said Ron.

“Every time the Time Turner is used,” said Kreacher, “another rock is put in the river. The flow changes again. And every time the Time Turner is used, it uses more magic to keep the rocks in place.”

“All the times I used that Time Turner in school,” breathed Hermione.

Harry’s veins flowed with ice.

“I would be dead now,” he said. “Without that Time Turner, Sirius and I would have been killed by those Dementors.”

“So if that particular Time Turner is destroyed,” said Hermione, “then Harry will die?”

Kreacher looked from Harry to Hermione and back, then nodded and lowered his eyes.