Harry had learned his lesson from the diary, and also from the fact that an above-maximum-level lich was going to imminently stop him: he lodged the basilisk fang in the Byzantine jewel with all his might and immediately dodged as far as he could away. Ekrizdis' half-aimed spell went wide. Black fire erupting from the piece of jewelry failed to catch him. And he even stuck the landing in front of Remus, who was whipping his own wand out to cover Harry.

Not that he needed to. One spell was all that the lich seemed to have in him, Elder Wand slipping nervelessly from his fingers. "How could you have known? How could you have prepared?" the undead wizard complained, his limbs losing their strength. "I was so close… to the stars."

What Harry had no way of knowing was that, in normal circumstances, the destruction of a horcrux would not instantly defeat the dark wizard that had created it. It was meant to be a backup, after all. But Gamp's laws were a harsh mistress, and the life-defeating tower of Azkaban was the worst possible place to exist for hundreds of years with no food for sustenance. Ekrizdis' body was little more than a mummified husk being puppeted by his wraith. Given enough time, he probably could have done bloody rituals to restore enough vitality that his once-mortal body would serve as another anchor for his spirit, but he hadn't actually expected guests, let alone ones who even knew what a horcrux was.

Unconscious by the time the fully-spectral wraith of Lord Voldemort had exited Professor Quirrell's body the previous year, Harry hadn't seen it, but the apparition leaving the lich's body was remarkably similar. However, not having Tom Riddle's particular madness of making more than one horcrux, that was it for ways Ekrizdis could hold onto the mortal world. The black, vaporous figure was barely free of the collapsing body before it simply unraveled into fog and vanished with a fading moan.

Harry could really barely pay attention to it, due to all the prompts crowding his screen.

SECRET QUEST COMPLETE
1000 XP Earned
Quest Reward: Increased favor with Death

There were secret quests? Death was a thing that he could gain favor with? It probably stood to reason that the grim reaper didn't like dark wizards living far beyond their allotted years, but still.

1103 Combat XP Awarded
Level Up!

Harry absently noted that Remus had leveled as well, both of them erupting in a shower of light and noise which probably annoyed the last fading remnants of Ekrizdis.

Finally, the Prisoner of Azkaban quest ticked over to its last objective, getting back to Hogwarts. Which turned out to be an actual objective, because the tower suddenly started to shudder. The burning horcrux had damaged the contraption it was lodged in, or maybe it was essential to keeping it stable, but the gearwork around them was suddenly going crazy. Timing chains were snapping, gears were jamming, and eldritch devices were making the kind of noise that nobody wants to hear in industrial machinery.

"We better get out of here!" Harry and Remus yelled at each other simultaneously.

Harry had the presence of mind to leap back over the now-inanimate corpse and withdraw the basilisk fang from the now-quiescent piece of jewelry. He also leaned down to retrieve Dumbledore's fallen wand, which seemed to practically leap into his hand as he bent down for it. Not thinking about it, Harry shoved both weapons and his gloves back into his inventory, and said, "Let's go!" Remus had already started moving as soon as he saw that Harry was going to be right behind him.

But he'd forgotten the loot! Perhaps delayed by how much inventory space he'd had, tools, clothing, and miscellaneous devices started to pop into appearance around Ekrizdis' corpse. "His stuff!" Harry yelled at Remus.

"No time! Leave it!" his defense professor yelled back, aghast.

"But!" Harry whined, then had a brainwave, "Send Ekrizdis' possessions to guild vault!" he yelled. Sure enough, the combat log noted the order, and objects stopped appearing around the dead lich. He stooped down and pitched a couple of things that looked like they might have value into his own inventory, then was off after Remus like a shot. "Open guild vault," he tried, as they reached the stairway back up to the living level. A window similar to his own vault interface appeared, noting that it was the Children of the Ark Guild Vault. It was teeming with icons representing stuff that he had no time to identify. "Professor! Wake up the others while I grab stuff!"

"As fast as you can!" Remus sighed, bowing to the inevitable. The entire tower was shaking, and he was very worried Harry was going to get himself crushed trying to loot the building.

At least having the presence of mind to realize that it was crazy to try to explore the rest of the floor (he wouldn't put it past the lich to put nasty wards on his private quarters), Harry focused on the sitting room they'd first entered. Television mirrors, prototype radio, and miscellaneous decorations: all into the guild vault panel. The biggest test was the bookshelf of skill books. Harry oriented himself to put the panel in exactly the right position so that he could literally just start tipping books off the shelf and into the interface, three or four at a time. By the time Dawlish was groggily waking up and retrieving his wand, the room was basically bare of anything smaller than a table or chair.

"What happened? Where's the berk? Where's his stuff?" Dawlish asked, noting that the room was much emptier than when he'd been stunned.

"Why is the room shaking?" Dumbledore asked the more pertinent question, especially concerned as he realized he was without his wand.

"No time to explain!" Harry told them, longingly looking back into the rest of the level and grudgingly closing the guild vault panel, really hoping it wasn't physically on the premises (or at least was heavily reinforced if it was). He opened his own inventory and grabbed the Elder Wand. "Here you go, sir!" As the headmaster's hand closed on the wand, there was almost a magnetic pull keeping it from leaving Harry's hand, but he managed to let go and considered that a problem for later.

Dumbledore looked sadly at the wand, but realized that he'd have to ask at another time. Now was for escape.

The room outside the dark magic wards was full of dementors. There had to be at least a dozen in the small half of a room that was cut off by the glowing blue runes. Perhaps they'd been queuing up after the three onlookers were driven off, or had noticed Ekrizdis' death and come to investigate. Harry realized the lich hadn't turned into another dementor when the horcrux was destroyed, so that was one worry down. But now the worry was whether they could get rid of all the dementors before the building collapsed. To Harry, the room was a whole sea of jumbled interface elements.

"Expecto patronum!" four men incanted, and silvery animals filled the room. Two large canines, a silvery phoenix, and Dawlish's European badger began to menace the cloaked figures. The ones at the front didn't seem inclined to give ground, mostly because they were blocked by the dementors behind. And then something unexpected happened. As Harry's wolf-dog imago made contact with the lead dementor, rather than being shoved back it wailed like a modem connecting and shattered. For Harry, it looked like the interface elements flared and vanished. The others simply saw the black cloak fall to the floor and then decay into mist.

The rest of the dementors started trying harder to escape the room.

"Well that's never happened before!" Dawlish realized.

"They may have owed their invulnerability to their connection with Ekrizdis," Remus surmised. "He's dead now."

"Still no time to explain!" Harry said, before the headmaster could ask for a debrief. "Get 'em!"

Several more dementors were torn apart by the contact of the four patronuses before the ones at the back managed to flee up the stairway. The room clear, the party charged across the wards and up into the giant ritual room. Dust was falling from the ceiling as the floor continued to shudder. "So many flights of stairs!" Dawlish worried, glancing at the secret staircase they'd come down on. "We're going to have to risk the tunnel." He looked sadly at all the mummified bodies strewn around the room, "I hope they're still identifiable when this is done. My crime scene!"

It was a straight shot to the escape tunnel, which only had a couple of mummified bodies along its winding length. After so long inside, it was a shock to finally escape out into the late-afternoon sky (for all that it was perpetually-overcast around the prison). In the last few steps onto the rocky shore, they had, indeed, passed through a strong illusion. Each of them tried to memorize the spot, just in case. There was quite a bit of uneven rock below them down to the water line, since it appeared to be low tide. "Do we walk around to try to get to the aurors?" Harry asked.

"Use your broom to go warn them," Dumbledore instructed him. "I'll transfigure a boat for the three of us." He frowned in concentration as he began doing so, the magic harder than he was used to with a no-longer-cooperating Elder Wand.

"His broom?" Dawlish asked, but didn't expect an answer. There was no time to explain, after all. But he'd be getting information later, he assured himself.

Harry had already started bounding down the rocky "beach" and withdrew his broom as soon as he broke line of sight with Dawlish, jumping onto the Nimbus 2000 and rocketing into the air to circle the island, slightly wary of the anti-broom charms but hoping that staying close to the water would protect him from getting sucked into the courtyard or blown out to sea.

As he rounded the building, he was thrilled to see that the magical boat was still moored at the pier. The auror that had brought them and the entry guard were both standing out on said pier looking up at the tower, which was clearly shaking in the afternoon light. As soon as he was in earshot, Harry started yelling, "Get everybody out! The tower might be falling apart!"

While a child on a broom he wasn't supposed to have didn't really have the authority to order an evacuation, he was the Boy-Who-Lived and the building was doing some terrifying and unexpected things. Permission from anyone to run for it was gladly taken.

By the time Dumbledore's transfigured boat moved around the island and into view (he had gone extra and given it a sail that he could push with wind charms), the half-dozen aurors that were the human staff of the prison had all exited onto the pier, and looked positively thrilled to see a senior auror and the Chief Warlock there to take responsibility for something they'd never trained for. Nobody had written a "what if the tower just starts to fall over one afternoon" procedure for the prison guards.

And the missing procedure certainly hadn't covered prisoner evacuation.

"Oh, dear, all those people," Dumbledore realized, looking toward the upper floors.

"No way to have gotten them down in time, or to make enough boats for them all," Dawlish frowned, not much happier at the situation. "At least minimum security wasn't very full right now, I think…"

And with that pronouncement, and all the prison aurors leaping onto the boat and moving it away, the massively-tall tower started to list. Clearly, something load-bearing had collapsed in Ekrizdis' machinery room, and the floors above were starting to buckle under the strain. "This never would have actually made it to space," Remus observed, as aghast as anyone else. The other two men on the boat looked at him in confusion at the seeming non sequitur.

Dumbledore blew his tiny sailboat away from the island and the aurors followed behind, Harry landing his broom on the deck of the headmaster's ship. At least they had some fortune: the weakest side of the building seemed to be the one opposite them. Once enough of the support structure had collapsed, the rest was sure to follow. The sound became immense as thousands of tons of stone ground against itself and snapped its mortar. The near side of the building was simply collapsing into the courtyard, but the far side was toppling over into the North Sea. In only minutes, Ekrizdis' tower—an edifice that had stood five centuries and was meant to carry wizards to the stars—was a just vaguely-triangular pile of rubble.

Look on his works, ye mighty, and despair.