Dumbledore didn't procrastinate, as Fleur told her mates. "He called for a staff meeting in which he announced he was going to resign and pass the position to Minerva, pending the board's approval, of course. He also said that the transition would happen gradually, over a period of several months and he would shoulder the transfiguration teaching to allow her to better learn her new duties. He intends to make a formal announcement to the school only before the winter holidays, hoping that the board will approve of Minerva by then."
It became evident during their next transfiguration lesson, when Dumbledore sat at the back of the class, watching everything. It could have been interpreted as inspecting the teacher, but Harry knew Dumbledore was just getting himself reacquainted with the position that he had passed to McGonagall many years earlier.
Two weeks later, the Prophet displayed a large heading, "Dumbledore resigns from ICW's Mugwump position". When reading the article, it became clear that Dumbledore also intended to resign from his position as Chief Warlock, but not immediately. He was quoted saying, "I've spent too many years in these positions. I'm too old to faithfully represent the majority of the British magical population. It's about time to let much younger people shoulder the burden."
\/\/\/
The curse-breakers continued working as usual. It didn't matter to them which member of the staff occupied any position. A week after finding the diadem, they found an old half-pound coin that reeked of dark magic. It didn't take much to identify it as the carrier of the DADA curse. The coin was cleansed and passed to Harry, to be used as regular money. They probably didn't know that this coin had been redrawn from circulation quite a few years earlier.
It took the team two additional weeks to sort and cleanse whatever needed cleansing in the Room of Requirements, adding quite a few valuables to the Potter vault. The two members that kept scanning the school also found quite a few remnants of curses and removed them all. The corridors felt much less oppressive and more cheerful after that treatment.
With the winter holiday approaching, Hermione suggested, "I think it will be best to scan the dormitories during the winter vacation, when very few stay there. Those few can even be moved to some other temporary lodging for the duration of the scan."
Harry fully agreed. He directed the team to finish checking the rest of the castle, leaving the house dorms and common rooms, along with the Chamber of Secrets for the winter vacation. With the DADA curse removed, he felt no urgency to finish the scan. He much preferred a more leisurely pace.
\/\/\/
The feast before the winter vacation turned quite a memorable event. As soon as everybody was sitting at their respective tables, Dumbledore stood up. "I'm glad to tell you that there are going to be some changes at school when you return from your vacation. First, I resigned from my position as headmaster. The board accepted my resignation and also agreed to name my deputy, Professor Minerva McGonagall, as the new headmistress of Hogwarts. She will take the reins by the time you're back at school."
This brought, as expected, quite a few surprised reactions. Dumbledore waited for the hall to quiet down before speaking again.
"You all know I'm old, it's not a secret. You may have also heard that magical people generally live longer than muggles. That's also no secret. It's a well-known fact that our magic protects us from many minor illnesses and injuries and corrects many others without us even becoming aware of it. That keeps us generally healthier than our muggle age-mates. Still, all we gain by it is about ten to twenty years, at most. It may seem a lot to you, at your age, but it's not that much when you look at it from my age. Muggles rarely reach a hundred years. Most don't even reach ninety. I've already passed the one-hundred-and-ten mark. That makes me old by any standard. As such, I feel that I can no longer take the burden of the headmaster of this school, nor my other positions. I already resigned from the ICW and I've now resigned from the headmaster position. I also intend to resign from my Chief Warlock position soon after the new year. This doesn't mean that you won't see me any more. In fact, you're going to see much more of me, as I will take over teaching Transfiguration to allow Minerva to give her full attention to her new position and do a better job at it than I did."
This brought another wave of reactions. Dumbledore just waited for it to subside and then waved his hand invitingly. "That's all I had to say. Now, tuck in!"
\/\/\/
The Potters didn't leave school the next day. As soon as the parting students boarded the train, Harry led the curse breakers to the Chamber of Secrets. The curse breakers wouldn't let anybody else join the group, but even they couldn't prevent Hermione from sticking to Harry's side.
Harry opened the entrance through Myrtle's bathroom and then Hermione stopped him. "I'm sure there's a more comfortable way than sliding through this. Why don't you try to ask for stairs?"
Harry frowned, unsure if that would work, but then shrugged and hissed "$Stairs$". He was surprised to see the slide turn into a wide staircase, quite comfortable to use.
"It would have still been quicker to slide down," he commented.
"True, but how would you come back here? You had Fawkes to help you then, but even that magnificent bird can't take the whole group with it."
"We could fly a broom," he tried.
"You left your broom in our apartment. Are you sure to find some down there?" She was evidently teasing him.
Harry shook his head. His mind was working much better since the treatment, but old habits, of doing things without thinking much first, were hard to change. He felt a bit ashamed of them.
Passing through the tunnel, they first reached the shed skin of the basilisk. Hermione gasped at its size and held Harry's arm tighter, almost painfully tight. She had already heard the story, even more than once, but seeing the evidence was quite unsettling.
The goblins had a different reaction. They seemed to measure it with their eyes and calculate its value in gold. They still said nothing.
They reached the caved-in tunnel a short while later. While Harry was still unsure about his ability to repair it, Hermione didn't seem to have many doubts, yet the curse breakers acted even faster. Within seconds, or so it seemed, that part of the tunnel was back to its original shape, looking cleaner than the adjacent areas. It was really nice to see how useful Magic could be.
As they approached the chamber, Harry wondered if he shouldn't advise the others to use some bubble-head charm or something similar, just for fear of the smell. He just wasn't sure how to say it without offending the goblins or making a fool of himself. Well, they could do something after finding out, he thought.
The next obstacle was the door to the chamber. Well, not for Harry. He quickly spoke "$open$" and the snake locks opened, letting the door swing aside. He felt Hermione's hold tighten on his arm.
Harry was afraid that the place would stink of the decaying basilisk carcass, unless it had been already stripped to the bones by various small scavengers. He was surprised to smell practically nothing, certainly not the putrid smell of rotting flesh. He was glad about that. He was also glad that the basilisk couldn't be seen from the door. He feared Hermione's reaction.
With the door open, the curse breakers took over. They walked cautiously in, scanning their surroundings and staying fully alert. The torches lighted along the wall as they advanced, yet they didn't seem to detect anything suspicious.
When they first approached the other end of the chamber and the torches finally lit at that end, they all stopped and gasped. The basilisk's carcass was lying there, looking almost alive, as if it was just resting before moving again. When Hermione saw it first, her hold on Harry's arm tightened beyond pain and she seemed to almost collapse, saved from that only by Harry's hug.
"You fought this?" she whispered.
The goblins didn't whisper. "Who killed this basilisk? The carcass is worth a fortune! It shouldn't be left here unused."
"I had some help," Harry started, only to be interrupted by the goblins again.
"You killed it? How long ago was it?"
Harry sighed. He didn't like talking about it. Even telling his wives was difficult. Now it looked like he had no alternative. "Yes, I killed it more than two years ago, at the end of my second year here. I was trying to save a student that was kidnapped by the memory, or maybe the soul shard, of Voldemort. The basilisk tried to kill me. Fawkes brought the sword of Gryffindor to me. It also poked the basilisk's eyes with its talons, destroying their killing ability. I then used the sword to stab the ceiling of its mouth. It managed to punch my arm with a fang, but Fawkes saved me with its tears."
The goblins seemed to have been stunned. Bill, who was with them, seemed to turn thoughtful after a short while. "That student, wasn't she Ginny?" he asked.
Harry nodded, knowing at once that he'd have to tell the full story a few more times.
Bill didn't hesitate. "Then, as Heir Weasley, I recognize the life debt my house has to you and declare the full support of house Weasley for you, your allies, and your descendants."
Harry had no time to reply, as a flash of light showed that Magic accepted Bill's declaration.
The goblin team leader returned to the main point, for him. "Since you killed the beast, the carcass is yours. How much do you want for it?"
Harry frowned. "I don't understand. I don't even know how to evaluate it."
Hermione was already recuperated enough to intervene. "It may be better to not sell it whole. I think it may be better to render it into smaller chunks and sell whatever we have over a long period. Selling it all at once may drop the prices too much."
The goblin nodded in agreement. "I'll ask for an expert to evaluate the carcass and suggest how to proceed. I still want to hear the full story behind this, but we have a job to complete. We can proceed from here. You don't need to stay with us for the rest of the day. We shall also make sure to keep the door open until we finish here, saving you frequent travels to this place."
Harry saw Hermione's relief. She'd seen what she had come to see. She was eager to leave that place with the huge snake that looked as if it would wake any moment.
This didn't mean that he could refrain from additional trips into that chamber. Fleur, who had reluctantly agreed to stay behind for the first trip, insisted on visiting the chamber as soon as possible, despite Hermione's advice. Then, Albus Dumbledore insisted on visiting there, and Minerva wouldn't be left behind. Harry took all three professors (including Fleur) together. They all gasped at the sight of the shed skin. When they spotted the basilisk, Fleur became tearful and hugged Harry as tightly as Hermione had done. Minerva didn't hug Harry, but looked just as tearful. Albus also had some unshed tears in his eyes, but he also looked very thoughtful.
"Severus would have liked to harvest this for potion ingredients," he said softly, not quite intending anybody to hear. Harry felt glad that he was saved from that confrontation. The way Snape had acted, he deserved nothing from Harry, so he felt.
The curse breakers didn't stay idle. Within a day, they found several more hidden passages that led to the chamber. They also found a few hidden rooms in the chamber, rooms that had evidently been in use by Salazar himself, judging by the thick dust covering everything. No curses were found there and no material valuables either, but a multitude of books and parchments was a different treasure, all by itself. Unfortunately for Albus, most of these were written in parselscript, unreadable to anybody but Harry. Well, according to the contract, they now belonged to Harry. Dumbledore only sighed, astounded at how stupidly he had acted for years.