When Harry returned to the Minister's office with Ron, Kingsley and McGonagall were already there, engaged in a heated conversation with Hermione.

"You can teach the children in those rooms —" Hermione trailed off and looked back at Harry. "Ah, Harry! Found anything in the forest?"

"I rescued Mr. Ollivander. He and the Dawn Breakers had been out picking wood for wands," said Harry. "From what I hear, Eisenbein wants to make some kind of weapon out of them. I didn't get the details, but . . . "

"Well, if you brought Mr. Ollivander with you, I guess we have less to worry about," said Hermione cheerfully. "We've been working on a defense plan, and Professor McGonagall thinks the students should still be taught here. I'm inclined to agree."

"She's right, Harry. Education cannot be suspended even in the midst of a crisis," said McGonagall solemnly. "The Hogwarts staff plan to use the Grand Meeting Room as a main hall, and classes will be held in empty offices throughout the Ministry."

"That's a great idea, Minerva. And Kingsley, I noticed a problem on the way here," said Harry. "The Muggle government has allied itself with Eisenbein. . . . They've got the police sealing off the passageway on the surface, and it looks like they're about to start digging underground."

"The Muggles? I knew something like this would happen," said Kingsley gravely. "Normally, in an emergency like this, I would have placed an Auror nearby to ensure the safety of the Muggle Minister; I, too, worked undercover in the Prime Minister's office during the last war. . . . But we were so short on Aurors that we couldn't afford it this time, and our enemies took advantage."

"It would have happened anyway. The Dawn Breakers would have teamed up with the Muggles sooner or later anyway," said Harry comfortingly. "After all, their whole point is to fight for all Muggles."

"That's true, but we can't just sit doing nothing," Kingsley said firmly before standing up. "With Mr. Prewett's help, I'm going to put a tracking device on the Prime Minister. . . . If I can place the tracker with a Concealment Charm on it, it'll come in handy when we need it."

"I almost forgot about the house-elves," Ron blurted out after Kingsley left. "It's just like the Battle of Hogwarts. We can't ask them to die for us, we have to get them out."

"Really Ron, you're so unpredictably thoughtful sometimes," Hermione said, looking lovingly at her husband. Ron returned her loving look and Harry coughed.

"If you're thinking of sharing a passionate kiss right now, I'll just tell you that we're at war," said Harry. "I'll call Kreacher and tell him to get the other house-elves to safety . . . Kreacher, come here a minute!"

No sooner had Harry finished speaking than there was a loud bang, like the explosion of a small bomb, and Kreacher appeared.

"Kreacher, it's not safe here anymore. You must take the other house-elves and find shelter."

"Master, this is ridiculous!" cried Kreacher, his huge eyes widening even more. "We house-elves would give our lives for our masters . . . Even in the last war, Kreacher fought alongside Master, taking his knife and cutting off the legs of the evil wizards."

"I remember that, and I'm still grateful," Harry said, lowering his posture to make eye contact with the house-elf. "But that doesn't mean I don't need your help — if we stay in here, we'll all be helpless prisoners. . . . Instead, you can go to a safe place with the other house-elves in the meantime, and then come back when we need you. Perhaps you can be of great help when the time comes."

"Harry's right, Kreacher. Dumbledore used to have the utmost faith in the loyalty and integrity of your kind," said McGonagall softly. "If you don't mind, Hogwarts is empty now, so why don't you go there? Maybe Peeves will be a little less likely to destroy the whole castle if there's someone there to look after the school."

Kreacher thought for a moment, then sighed heavily. "Very well, Master Harry, Kreacher will do as you ask. . . . But please do not hesitate to call on the humble house-elf if Master needs me."

"Of course I will."

The house-elf nodded and with a snap of his fingers tried to Disapparate. But strangely, the loud bang that usually accompanies the Apparition of a house-elf was missing, and Kreacher remained where he was, with a puzzled look on his face. Just as the elf was about to snap his fingers again, there was a sudden knock and the door to the office burst open to reveal Teddy. He looked back and forth between the frozen house-elf and Harry and said, "I guess I was right after all . . . Kreacher can't Disapparate now, can he?"

"That's right, how do you know?" asked Harry.

"I think there's an Anti-Disapparation Jinx all over England right now," said Teddy darkly. "That's why I went to the trouble of bringing my guests here. I was wondering if Eisenbein had also blocked the Disapparation and Apparition of the house-elves, and I guess he hasn't forgotten that either . . . "

"Well, Master, then Kreacher and his fellow elves will take care of it from here," said Kreacher. "Kreacher's kind still have plenty of ways to hide from Muggles, he'll do what the headmistress suggested and stay at Hogwarts."

"Please do. I'll see you later, my dear friend."

"I'll talk to the house-elves and explain how to get into Hogwarts," McGonagall said as she prepared to leave. "There are all sorts of defensive spells around it now, and they'll have a hard time entering . . . "

Kreacher looked at Harry with wistful eyes before bowing so low that his long nose touched the floor. Once he and McGonagall were gone, Harry turned his attention back to Teddy.

"You brought a guest — who?"

"You gave me a job to do and you forgot it already?" Teddy snapped and opened the door. Accompanied by Bill Weasley, a small, fair-skinned creature less than half his height strode into the room. It wasn't until the goblin squinted as if surveying the room's occupants with clever eyes that Harry realized who it was: it was Griphook, whom Harry and his friends knew only too well. It was their first face-to-face encounter with him since he had helped Harry sneak into the certain vault of Gringotts long ago to steal Hufflepuff's Cup.

"Hermione, I've been to Gringotts Bank as an emissary for you," said Bill, "and Mr. Griphook said he wanted to see you in person —"

"You!" Ron shouted, jumping to his feet. "You left us in the vault to die, and now you come here to —"

"Wrong, Ron Weasley. You were the one who tried to trick me in the first place," Griphook spat. "You were supposed to give me the sword of Ragnuk the First, but then you decided to take it somewhere else, thinking I wouldn't notice. . . . In the end, you somehow managed to conjure it out of my hands and steal it from me with a dirty hat. But you wizards must have some kind of spell on your heads, because you only remember things that work in your favor. . . . How convenient."

"Ron, how many times have I told you to forget old grudges?" Hermione gave Ron a warning look and looked back at Griphook. "As you say, both Mr. Griphook and we were at fault in the Gryffindor sword affair, so let's call it a draw and move on. By the way, what do you think of my proposal?"

"Your suggestion that we goblins come to the aid of your wizards and fight alongside you? My people thought long and hard about it, and sent me, the one who knows you best, as their messenger. Ordinarily, we would have refused in a heartbeat, but —"

"Things are different now, aren't they?" said Harry. "I was there the day they raided Gringotts. . . . Eisenbein and his men mercilessly slaughtered a bunch of goblins guarding the bank, and their bodies were strewn everywhere."

"That's right, a grudge we'll remember for generations," Griphook said through clenched teeth. "Two of my relatives died that day too, and if there's any people in this world more evil than wizards, it's Muggles . . . "

"So you'll help us?" said Ron hopefully. Griphook ignored him and studied Harry's face as if examining the surface of a gem for flaws.

"You're a very strange wizard, Harry Potter . . . " said Griphook finally. "You saved my life, you dug a grave by hand for a dead house-elf, and you borrowed our ledger when you had every opportunity to cheat us, only to take the blame and hand control of Gringotts back to us."

"I've heard similar sweet praise from you before," said Ron bluntly. "You abandoned us soon after. Are you going to help us or not?"

Griphook once again ignored Ron's comment and continued to look up at Harry, running his long fingers through the thin gray stubble on his chin.

"If we have to work with wand-carriers, only you can be trusted, Harry Potter," said Griphook quietly. "There are many of our kind who revere only you and despise all other wizards. But I'm afraid we can't help you."

An uneasy silence fell over the office. Harry, Ron and Hermione looked at each other and exchanged disappointed glances. Griphook stroked his thin beard in silence before finally speaking.

"Harry Potter, as you said, our grudge against the organization that calls itself the Dawn Breakers runs very deep. . . . But we goblins are a quick-thinking race, and we are not fools enough to risk our lives in an unwinnable battle to settle a past grudge."

"Think we're going to lose?" said Ron sharply. "You know why? Because everyone else is turning their backs on us! You think if you just keep your heads down, the war will be over —"

"Just wait there, Ron Weasley. It's not like we can't help," said the goblin. "As you all know, we're very good at taking care of our interests. . . . So if we think you can win, there's no reason why we shouldn't be on your side."

"Then what are you going to do to make us believe you?" said Hermione desperately. "We're ready to fight, we're ready to die, we're ready to defend our world!"

"Determination is not the only thing you need to win," said Griphook. "In war, numbers matter . . . And from what I hear, the magical creatures of the forest, including the centaurs, have refused to help you."

"So that's a condition?" said Harry. "If the other magical creatures help us, then the goblins will help us, right?"

"Something like that," said the goblin. "Because if they don't, we'll end up looking like a bunch of petty house-elves clinging to their soon-to-be-dead master . . . "

"Hey, don't talk about house-elves like that!" said Hermione, looking annoyed. "Just because they're innocent and kind doesn't mean they can be ridiculed!"

"I knew you'd say that," Griphook chuckled. "That's why I like you people . . . you're so stupidly nice. Good luck with your war."

As Griphook left with Bill and Teddy to return to Gringotts, the remaining Harry, Ron and Hermione slumped in their seats and let out a long sigh. They were going to have to fight this alone, after all, and it didn't take a goblin to know that if they fought alone, they would lose.

"No matter how hard we try to deny it, our fate rests on that old prophecy of the centaurs," said Harry. "The goblins won't help unless the centaurs help, and the centaurs won't help unless I'm a wizard."

"Then the fate of our world depends on whether you can break the Fourth Curse and become a wizard again," said Hermione quietly.

"There is a way, Faraday told us before," Ron said, a hint of hope in his voice. "He said there was a machine underground in Azkaban. A machine that might be able to reverse the Fourth Curse."

"The chances of that happening are extremely slim," Harry muttered. "It's almost certain that the creator of the machine, Ekrizdis, used it to break the Fourth Curse on himself, but he's never been seen since, has he?"

"I don't think so, Harry," said Hermione worriedly. "You might as well use it and disappear from this world forever!"

Ron's expression, which had brightened for a moment, immediately darkened and fear of losing his best friend filled his eyes. Harry fell silent, weighing his options. He could either risk his life and use the machine to become a wizard again, or he could stay here as a Muggle and fight for his friends. . . . The first option would almost certainly get him killed, but if he chose the second, he would lose the war, and that would condemn not only him, but everyone he loved to eternal misery.

"It's still worth a try," said Harry firmly. "But before we can do that, we need to find out more about this machine."

"Are you sure you want to do that, Harry?" Hermione said, her voice trembling, and then, as if reluctantly, she took a piece of purple paper from her desk and began to scribble. "I'll call Faraday. He's been researching Ekrizdis and the machine he built at the Department of Mysteries. I'm sure he should have a lot of information by now."

Waiting for Faraday to arrive, Harry sat and felt the anxious eyes of his two friends flicker over him. It reminded him of the reactions of the other students after Professor Trelawney had first predicted his death so long ago. As Harry imagined the many grim ways Ekrizdis could have met his death, there was a knock at the door and Faraday entered. Carrying an armload of parchments, books and journals, Faraday placed them on the long table.

"Here is everything I could find on the Fourth Curse and Ekrizdis's machine to break it," Faraday said, stretching his back. "However, since there wasn't a proper Ministry of Magic when it was discovered in Azkaban, the information contained here is very fragmentary."

"Oh, so you're saying we don't even know how the machine works?" said Hermione. "Well, if Harry's going to use it, he should at least make sure it's safe."

"At least I know what it looks like, here's a sketch." Faraday picked up one of the parchments and unfolded it on the desk, revealing a drawing of a complex machine. It centered on a skeletal sphere with several structures supporting it from below, vaguely reminiscent of a broken globe. "And here," he continued, "is a manual confiscated from Ekrizdis's laboratory by officials of the old Ministry of Magic, listing the parts that make up this thing and its shape."

He pulled out a thin, leather-bound tome. Inside were drawings of parts that resembled hourglasses, parts that looked like very large batteries, and components of unknown purpose such as various copper wires and large and small pieces of glass.

"Cool," Ron marveled at the intricate drawings. "How did he make something so complicated all those years ago?"

"I was surprised too. That wizard named Ekrizdis, as evil as he was, was more skilled at building machines like this than any other engineer," Faraday agreed. "Perhaps even then he realized the truth that science has greater power than magic."

"But how do you know it's safe?" said Hermione.

"I don't know that either. . . . There's no book anywhere that tells you exactly how this machine works," said Faraday. "But with this journal, there's still room to find out."

Hermione snatched the thin black notebook from Faraday's hand and studied its contents. Ron, who had been sitting next to her, stood up and read it with his wife, but his expression quickly turned to one of confusion.

"You say there's a clue here, but there's nothing written!"

"Oh, I see!" exclaimed Hermione. "Ron, don't you remember? Riddle's diary seemed to be empty too!"

"Exactly, because this works the same way as that diary," said Harry. "I've already used it to look into Ekrizdis's memories with Kingsley. . . . But Faraday, I didn't see any of these machines in those memories back then."

"There's a reason for that. That particular part, the last part of his memory, is encrypted. I found it when I was writing things down myself," said Faraday. He took a quill pen from the desk, dipped it in ink and wrote in the journal, "I want to know about a machine that can break the Fourth Curse." The black letters on the page glowed for a moment, then faded as if absorbed by the paper, and a new sentence appeared in their place: "Write what I wish to be."

"So we have to write the answer to that question?" said Ron, confused. "If I were Ekrizdis, what would I want to be? The most powerful Dark Lord ever? Or master of Death?"

"No, at the time of this writing there was only one thing Ekrizdis wanted to be," said Harry quietly. "He was struck with the Fourth Curse, and in his desperation to break it, he built this machine. . . . He was in the same position I am in now."

Harry took the quill from Faraday and wrote the answer, "WIZARD," in the journal. The effect was instantaneous. The pages of the book fluttered and turned as if swept by an imperceptible wind, stopping only when they reached the very last chapter. In the middle of the last page was a landscape of a darkened place, as small as a smartphone screen. Suddenly, everyone in the room leaned forward, and as the screen grew larger and larger, they were sucked headfirst into it, like being sucked into a giant vacuum cleaner. A dizzying swirl of colors and shadows spun around them, like the Floo Network or a Portkey. . . .

When Harry finally stepped onto solid ground, he found himself in a small room in an underground crypt he had visited before. Ron, Hermione and Faraday, who had arrived almost at the same time, huddled shivering at his side. In front of them was a man sitting on a very dilapidated bed that looked like it might fall apart at any moment. He looked extremely unsteady, the hand holding the journal trembling and his eyes darting around the small room to check on the intruders.

"Is that Ekrizdis?" said Ron as he approached the bed. "The old stories said he was a very scary Dark wizard, but he looks too shabby."

"That's because he's not a wizard anymore," said Harry bitterly. "I don't know how it happened, but at some point he fell under the Fourth Curse and lost all his magical abilities, and the last time I saw him he was giving his wand to a house-elf to do magic for him whenever he needed it."

"Shh, he's trying to say something," said Faraday. Sure enough, Ekrizdis was now holding a quill and scribbling in his journal, muttering something.

"It's finally done. . . . The Machine of Reality, painstakingly crafted from information gathered from the deaths of countless test subjects, is about to be activated . . . "

The group held their breath, listening intently to Ekrizdis's almost trance-like monologue. The Machine of Reality? Was that the name of the mysterious contraption in Azkaban's underground?

"But there remains one problem. Access to the barely finished machine is not easy," Ekrizdis said, speeding up his writing in his journal. "With the crazed house-elf and dementors swarming around the machine, getting to it is no longer a simple matter. . . . In addition, it is still impossible to find the Deathly Hallows needed to use the machine safely. Even the Elder Wand, the only one of the three sacred items I've been able to find, has fallen into the hands of the mad house-elf, making it difficult to secure."

His thoughts were interrupted by an unpleasant sound from outside. It was a sharp, harsh noise, like the grinding of a blade against stone. Ekrizdis stopped writing in his journal, startled, and looked up.

"Dear Master, where are you? Mealtime is coming . . . "

The voice came from outside the tightly closed door. It was a thin voice that seemed to belong to a house-elf, but unlike those of his kind, it was venomous and filled with insanity. It was clearly Menetti, the house-elf driven mad by the misdeeds of Ekrizdis. Then, with a creak and the sound of another door opening in the hallway, Menetti spoke again.

"Master, Menetti has prepared a most delicious stew. . . . But Menetti's running out of ingredients . . . he just needs some fresh meat." Once again, the sound of a door creaking open could be heard in the corridor outside. "Ah, but he can smell it. . . . He's got some very fresh meat squirming around here somewhere. . . . Just wait a minute, Master! Menetti will be back with the tasty stew!"

Ekrizdis scrambled to his feet, his face pale with fear. Clutching the journal, he slowly approached the door, opened it a crack and peered out. Harry moved to the crack to see what he was looking at. Outside was a narrow, darkened den, lit only by the dim glow of a wand held by a petite house-elf. With his other hand, Menetti held a kitchen knife that was very large for his size, and with every step he took, the blade clattered to the floor, making an unpleasant metallic sound. Just then, Menetti, who had just opened another door, abruptly turned his head and looked at the door they were in. Harry couldn't help but feel goosebumps all over his body, even though he knew this was someone else's memory and the house-elf couldn't hurt him.

"Master, Menetti's found the meat!" the elf shouted, his mouth wide open in a horrible grin.

Ekrizdis flung open the door and ran out of the crypt, fleeing deeper and deeper. Right behind him, the mad house-elf giggled and chased after his master. Without being told, Harry and his friends ran along the crypt, dodging the house-elf who was dragging a sharp knife behind him.

"I take it you don't like house-elves any more, Hermione?" said Faraday, panting.

"No, not at all!" cried Hermione. "This is what you get for being mean to house-elves!"

The tunnels, pitch black at first, barely showing Ekrizdis's black hair as he ran ahead of them, brightened slightly as they progressed, illuminated by a faint green glow in the distance. When they finally emerged from the narrow tunnel, a large cavern appeared before them, lit by green lanterns floating near the ceiling.

As the darkness that had initially obscured their view thinned, Harry nearly screamed at the sight of the black figures that filled it. Ron and Hermione gasped as well. There must have been hundreds of dementors roaming the cave. Harry hadn't felt their chill from his memories, but he could see how cold it was when Ekrizdis' terrified breath condensed on contact with the air. Ekrizdis shivered and froze.

The fog on the cavern floor rose higher and higher, submerging him up to his neck as the dementors, seeing an easy prey, surrounded him and crept in. Harry heard his mother's faint screams in his head. . . . Ron blinked very fast, his shoulders shaking slightly, and Hermione clutched her husband's arm and squeezed her eyes shut. Only Faraday seemed unharmed, watching the dementors and approaching them with more curiosity than fear. The dementor closest to the victim reached out a corpse-like hand covered in sticky slime. . . . The growling breaths grew louder with excitement; it would now suck the very soul of its creator. . . .

Then Harry heard a familiar sound from the crypt and turned to see Menetti stomping into the cave, his knife dragging behind him. His mouth, now grinning broadly, was dripping with drool, and his eyes, as big as tennis balls, were focused on his master, ignoring the dementors.

"Master, your humble servant has found the meat!"

Menetti pounced, and Ekrizdis, curled up in a stunned heap, opened his eyes and scrambled away. The dementors suddenly retreated, as if they had found an interesting spectacle, and watched the chase in the cave. Clutching the journal tightly, Ekrizdis ran toward the shadowy spot on the other side of the cavern's entrance, his house-elf close behind him, wielding a cleaver. . . .

As they ran, the darkness was gradually lifted by the light from the tip of the wand held by the house-elf, revealing a certain object. It was the Machine of Reality that Faraday had just shown the others in the drawings. Smaller than Harry had expected, the machine was skeletal, a few bent steel beams forming a sphere. In the center was a wide plate, large enough for a person to lie on, and Ekrizdis pulled down a lever on the machine and lay down on it.

The cogs beneath him creaked and turned, and soon a thin sheet of iron emerged from between the skeletons of the sphere, completely obscuring the central plate and Ekrizdis. The crazed house-elf arrived, screaming maniacally and slashing at the machine that had turned into a metal sphere a few times with his knife, but it didn't stir except for a few sparks. The skeletal structure around the sphere spun quickly, and a humming sound came from the machine.

"I'm so close to finding the meat . . . and it's right here!" shouted Menetti, tirelessly hitting the steel surface with his knife.

Finally, the skeletal structure stopped spinning and fell back into place, and the iron panels covering its exterior disappeared, revealing the inside of the sphere. But Ekrizdis was nowhere to be found, and on the slab where he lay there was only the research journal with the black cover.

"No . . . Master must be hungry!" shouted Menetti. The house elf climbed over the machine, knife in hand, picked up the journal, and crouched down. "Menetti needs to make a stew, but he has no meat. . . . He wishes someone would come quickly!"

The sight of the house-elf sitting on top of the machine with a blank expression and the dementors prowling around him swirled in front of them, and then suddenly there was a thick, silken darkness, and at the same time Harry's body fell downward.