On the second of September, Harry and the other Sixth Year remained in their places after breakfast, awaiting Professor Dippet's descent from the staff table. The distribution of class schedules was more complicated than usual, for the deputy headmaster needed first to confirm everybody had achieved the necessary O.W.L. grades to continue their chosen N.E.W.T.s.

To nobody's surprise, Albus had elected to continue almost every subject he's been studying the five previous years and had merely dropped History of magic to replace it with Alchemy.

"You're going to be very busy," Professor Dippet remarked as he charmed the prefect's timetable. "I know you work hard, but my colleagues and I expect our students to do a lot of work outside class. I hope it's not going to be too much for you."

Albus amiably smiled. "Duly noted, sir."

When it finally was his turn, Harry told the Deputy Headmaster he wanted to take Charms, Defense Against the Dark Arts, Herbology, Transfiguration, Potion, Divination and Alchemy.

"As I told Mr. Dumbledore, you're going to be very busy if you take so many classes. I've heard from your Head of house that you wanted to become an Auror. Are you really sure you want to pursue Divination and Alchemy when these courses will have little relevance for your chosen career?"

"Certain."

While it now appeared there was a way to leave this century, Harry didn't want to take any risk and drop Divination too soon. If he wanted Professor Mesmer to keep helping him, he needed to take his class. Also, Albus had strongly implied the year before that Alchemy had many hidden depths so it might just be possible he'd find something new on time travel. As he's come empty handed with the regular magical courses, he couldn't ignore it.

Still, he couldn't stop a wince at the sight of his timetable. Considering he also had to take into account Quidditch trainings, Harry knew that finding time to study time travel this year was going to be nigh impossible.

"Before I forget," Professor Dippet remarked, "the Headmaster asked me to tell you that you are expected in his office after class. He said you should know why."

Harry sighed. "I do."

As expected, Phineas Nigellus Black hadn't forgotten Harry owed Hogwarts money. And it seemed that it was now time to pay his debt.

Once the older wizard left the Gryffindor table, Albus raised an eyebrow.

"It's nothing," Harry reassured him. "Just- I just need to give him something. It'll only take a minute."

Checking his timetable once more, he noticed his first class of the year was Defense Against the Dark Arts. Stuffing the timetable in his pocket, he took his bag and got up.

He wondered what sort of person the Defense teacher was going to be this year.


"Good morning class," Professor Merrythought greeted the Sixth Year students. "First thing first, I want to congratulate you for your excellent marks in Defense Against the Dark Arts as you-"

"Wait, you're still here?"

Professor Merrythought paused. Looking in the direction of the scream, she tilted her head and in a confused voice wondered, "Why wouldn't I be?"

Harry gaped.

After a long pause, Professor Merrythought went back to her speech. "As I said, congratulation to all of you. If you are here today, it is because you have all proved that you have solid basis in Defense Against the Dark Arts and can now handle low to mid-level threats. Now that you've decided to prepare your Nastily Exhausting Tests, your other teachers and I expect you to go beyond what you were taught for five years and-"

Albus softly pocked the boy next to him and whispered. "You okay?"

Harry slowly turned his head in his direction. "I've never had a Defense teacher that lasted more than a year," he stated in a small voice.

Albus drew back at these words. "Well… It's a good thing she's still here, no?" he tried. "Professor Merrythought is an excellent teacher, don't you think?"

"You're really sure it's her?"

Albus paused. "Well… yes?"

Harry blankly looked at him for a few uncomfortable seconds. Finally, he turned his head and suspiciously looked at their teacher.

"I should warn you: the curriculum in Defence Against the Dark Arts is so vast it will be impossible for us to study everything in class and if you want to be ready for your examinations, you will have no choice but to study several subjects on your own," Albus head Professor Merrythought telling the class. Retrieving from her satchel a pile of parchments, she handed it to the students in the front row who began distributing what she had given them.

When Albus looked at what appeared to be this year's curriculum, even he couldn't stop a wince.

"Considering my colleagues will tell you the same thing in their respective subjects, I strongly encourage you to give your very best immediately because you will be unable to have a passing mark were you to start studying seriously a month before the end of the year like some of you probably have in the past. Still, were you to have any question, my colleagues and myself will be more than ready to answer them and lend you a hand. As this is going to be the first time for many of you to work independently, I have decided to try something that should help you. This year, I will not ask you to hand me homework."

There were a few relieved sighs.

"What I will ask however, is for you to hand me at the end of the year something approaching a research project. Now, this will represent your only marked work so I advise you to treat it seriously."

That made him turn his head. "A research project, Professor?" Seeing her look at being interrupted, he sheepishly raised his hand. When she finally allowed him to talk, he asked, "May we know which subject you want us to study?"

"I'll let you decide," she answered him. "The goal is for you to research and study in depth something you're interested in, and to potentially go further than what you may find in the library. Of course if you still have no idea by October, I suppose I can give you a few ideas. At the end of the year, you will present hand me your project before presenting your work to the rest of the class so that you can benefit from everybody's work."

Albus beamed.

This wasn't that different from what he's been doing in his free time. Only it was now an actual research project, one he would have an entire year to study in depth and not just a few thoughts put on paper. Already he could see himself searching the library for something exciting, or testing yet another spell to see how far he could go until something strange happened. Perhaps he would even discover something utterly new and Professor Merrythought would be so impressed that project of his would be sent to Defense and the Dark arts .

And this time, it wouldn't be Albus Dumbledore, child genius, who would send it. No, it would be Albus Dumbledore, researcher.

He might even get a real prize for this. Not one of those which was given to to what they called 'promising youth', it would be one they gave to actual researchers. It would be one that said they were finally seeing you as their equal and not some talented kid they just needed to pat on the back while the camera was on them before leaving without a word once the journalist was gone.

And who knew? Perhaps Albus would find something utterly groundbreaking and he would also get a chocolate frog card for this discovery.

While Albus was considering what he was going to ask them to write on the back of his future chocolate frog card, Professor Merrythought continued, "I know that some of you will find this a little boring. It will ask you to put a lot of work into it and this sort of work can be very stressing. This is why I believe it would be better if you do it in groups of two."

From the corner of his eyes, Albus looked at Harry, who was still looking at Professor Merrythought in suspicion.

The Gryffindor was excellent at Defence, he thought. And the two of them got along quite fine, even if the boy could sometimes be rather queer. Still, it wouldn't be bothersome if they were to spend more time together. No, it wouldn't be bothersome at all. The wizard could even be could be an invaluable help in his research and perhaps they would compare notes over a nice cuppa in Hogsmeade. And maybe over a conversation they could talk about other things a little more personal and just like that they would-

"-Albus?"

Albus forced himself to snap out of his reflections and turned his head to his left. "Yes?"

Elphias grinned. "Great. I'm looking forward to it."

… Apparently, Albus's just agreed to do something.

A little legimency probing informed him that while he had been busy daydreaming, Elphias had asked him if he wanted to partner with him for this research project. And Albus has just said yes.

That was fine, he thought. It wasn't as if he was disappointed or anything.


When Harry left the Defence Against the Dark Arts classroom, he sent one last suspicious look to Professor Merrythought.

If that person really was Professor Merrythought.

Albus sighed. "Is it that surprising for you that a good teacher stays for more than a year?"

"You'll understand one day."

That reminded him, Harry had yet to tell the other boy he was from a future where the other wizard was forced every year to find somebody stupid enough to accept a cursed job.

The auburn-haired blankly looked at him. Finally, he closed his eyes and softly shook his head. Without saying anything, the boy started heading to Transfiguration.

Harry promptly followed.

Considering it's literally been a year since he's been in the past, Harry guessed there was no rush in telling him at this point.


Sixth Year, it turned out, was a lot more difficult than Fifth Year.

In Potions, Professor Prince asked his students to brew a Draught of Living Death. And if Albus as always perfectly succeeded on his first try, Harry's looked more like liquid licorice.

"The Draught of the Living Death is a very complex potion to brew," Albus tried to console him after Potions. "I believe in fact that Professor Prince gave us a potion nigh impossible to make at our level so that we can see how far we still have to go."

He shrugged. "If you say so."

"I know so. You just- You just need to work harder than ever."

But the more classes they had, the more Harry realized he had to work 'harder' at basically everything.

The days everybody thought he was some sort of genius, Harry thought as his latest attempt at casting the aguamenti charm failed once more, were definitely over.


It was an exhausted Harry who climbed the stairs of the Divination Tower for his last lesson of the day.

He had no idea what Professor Mesmer was planning to teach them as there had been no textbook in his list but he sure as hell hoped he wouldn't give as much homework as Prince.

When Harry entered the classroom, he stopped.

The divination classroom has always been the oddest classroom in the school. In the twentieth century for example, Professor Trelawney's many lamps she had draped with dark red scarves and the smell of incense had often given him the impression he was in a gypsy-wagon. Professor Mesmer on the other hand had elected to favour natural sunlight and had put numerous paintings of eyes that would spy on unsuspecting students.

But there now was a new artefact in the room that was holding the attention of the painted eyes.

It was a mirror. More precisely, a large tilting dressing mirror was standing in the middle of the room, as if it was a magical artefact of great importance. For a second, Harry even thought this mirror was the mirror of Erised.

But when Harry walked to the mirror and looked at his reflection, his parents didn't appear to give him encouraging smiles, nor did his reflection start talking back.

Unlike the one he had found one night in a disaffected classroom, this mirror seemed to be just an ordinary mirror.

Harry wondered where the mirror of Erised could be in this time.

In the reflected surface, Harry saw Phineas Black entering the room.

After closing the door, the Slytherin walked in his direction to stand next to him. Looking at their reflection, he hummed, "Looks like a regular mirror to me. You think this is related to what Professor wants to teach us?"

"No clue." Finally tearing his eyes from the mirror, he turned to the boy. "Where are the others?" he wondered.

And Black gave Harry a look .

"Potter, you and I are Professor Mesmer's only Sixth Year students."


"Good morning, class," Professor Mesmer greeted them when he finally came with a large pile of books. "I hope you all had very pleasant holidays." After putting the books on his desk he turned to them. "First thing first, I've been told congratulations were expected when one was teaching Sixth Year students. So I suppose I should start with congratulating myself for finally having a Sixth Year class to teach and getting the subsequent salary raise that comes with it. That was well-played if I may boast a little."

Black closed his eyes and took a deep breath. "You're supposed to congratulate us, sir."

"Well, that doesn't make much sense. I'm the one who did all the hard work here." Seeing the Slytherin's unimpressed look, he rolled his eyes. "Fine, fine. Mr. Potter, congratulation for mentally torturing a poor pregnant woman; Mr. Black, congratulation for stalking your examiner for an entire week and setting in motions several incidents you just happened to have predicted. I'm sure the two of you are very proud of yourself."

The two students uncomfortably shifted on their chair.

"I wasn't going to mention it but if that's how it works, congratulation to the two of you for being terrible people."

After a long pause, Black replied, "Congratulation on your raise, sir."

"Why, thank you." He clapped his hands. "Now that this part is done, let's talk about why the two of you are here: for three years, you have both learned to predict the future by reading tea leaves, the palm of a hand even even by crystal gazing. All in all, you've learned nothing."

At the sight of their face, the seer shrugged. "These are just tools, and not even the most powerful ones we've got. Don't get me wrong, they've got their uses but they are just the compass you are going to use to see the future. And any sailor will tell you that while it is damn vital to know how to read the map, it takes more than that to bring a boat to its destination. As you've decided to navigate the flow of time, it is time for the two of you to learn why what little you were taught works, what to do when you're not sure about which path to take, and what you may be facing on your journey. We're about to study in depth one of the most obscure branches of magic, so I should warn you that you may just lose your sanity if you're not careful and stare into the abyss too long. Any question so far?"

Very slowly, Black his hand. Once their professor allowed him to talk, the Slytherin took a deep breath, as if bracing himself. "May we- May we know why there is now a mirror in your classroom, sir? Is it related to what you're actually going to teach us?"

"What, that?" He turned his attention to the artefact in the middle of the room. "No, this is for me. I've realized something during the holidays and am now attempting to see if I can discover the answer to divination greatest mysteries if I stare at my reflection long enough."

Some people, Harry thought, have definitely stared into the abyss too long.


After their lesson, Professor Mesmer handed the two of them the pile of books he's come with.

"I want the two of you to have finished reading them for the end of the month."

While Black took a heavy grimoire on astrology with a long-suffering, Harry looked at the title of the nearest book. "Professor, this book is about arithmancy, not divination."

"Arithmancy," Professor Mesmer said, "has two greek roots. The first one is arithmos which means number ; the second one now is manteia which, surprisingly, means divination. Chiromancy, pallomancy, arithmancy… Anything finishing with the suffix -mancy belong to the large family of divination arts. Arithmancy is the art of divining the future by the usage of numbers. I teach divination, therefore I also teach arithmancy. The class your classmates take is merely a watered down version of divination as Professor Scalaria is teaching not even a tenth of what I do."

Black's eyes widened in realization. "So that's why she hates you."

Mesmer hesitated. "It's not just that but it sure doesn't help. You two have a month to catch up. Come September, I will consider you've got the same level as any student who sat Arithmancy for their Ordinary Wizarding Levels." Seeing Harry's wince, he shrugged. "The 'Exhausting' in Nastily Exhausting Levels Test is here for a reason. We only have two years, and we need to do twice the work you two have done in five. So brace yourselves, because even without my third eye, I can see the two of you are going to have a very tiring year."

Harry sighed and wordlessly took the arithmancy book. Once he and Black decided who was taking what, he remembered he was supposed to go to the Headmaster's office.

Suddenly realizing he had no idea what the password was, he asked Black, "Sorry, do you know the password to your dad's office?"

Black blinked. "You mean Professor Dippet didn't tell you?"

"Dippet is always a little air-headed," Mesmer commented as he was closing the curtains. "Believe me, there is a reason why Professor Black is always after him."

"It's Bellatrix." Seeing Harry's face he shrugged. "My father always uses the name of a star for his passwords." Checking his pocket watch, he winced. "You should hurry up, because if you're already late."

"And don't worry too much. After the first thirty minutes, you stop feeling anything and it becomes even relaxing past the second hour."

"What does?'

But the man never answered.


"Bellatrix."

Harry sighed as the gargoyle moved to reveal the door leading to the Headmaster's office. After attempting to flatten his unruly hair one last time, he took a deep breath and knocked.

"Enter," he heard.

Harry opened the door and entered the Headmaster office.

Like the last time Harry's been here, Phineas Nigellus Black was sitting in his armchair, hands crossed. "You're late," the man informed him. "You're very late."

"My apologies, sir. My class of the day was divination and Professor Mesmer's-"

"Say no more." The other man shook his head and sighed. "I will have a talk with him later on this specific subject. Again." Turning his dark eyes in his direction, he said, "I hope for you that you know why I called you here."

"I do."

Walking in the man's direction, he started searching his pockets. Once he found his galleon, he put the coin on the table between them.

"Thank you for your patience, sir."

Harry knew the wizard in front of him could have asked him to pay back the money Hogwarts' given him at any time. While he couldn't have found a mean to pay back until the holidays, he was aware the stern man could have harassed him at any time had he so wished.

Phineas Nigellus Black glanced at the coin on the table. Retrieving his wand, he put it on the galleon which emitted a golden glow.

"It appears that this galleon is genuine," he finally declared. "So I suppose that this is satisfying for the time being."

When Harry heard these words, he couldn't stop a relieved sigh and felt like an enormous weight had just been lifted off his shoulder.

And then he actually thought about what the man's just said.

"What do you mean by 'for the time being'?"

"Why do you mean by 'for the time being', sir ,"' Phineas Nigellus Black sharply corrected. "Well, you have yet to pay the interest, don't you?"

The world came to a sudden halt. "What interest?"

Talking to Harry like one would a not very bright kid, he explained, "You received money from our school. Money you spent for your personal uses while Hogwarts had to make without. The school doesn't give money away for no reason and we are not your mother you're borrowing money from. In the real world, what you received from us is called a loan. And Hogwarts is perfectly within its right to ask you for interests. As you paid back the galleon you were given, I suppose I can allow you to pay the interest until next year. But that truly is the last time I am going be this lenient and-"

"Lenient ?" Harry spluttered, "Y-You never said anything about interests! You-You-"

"You haven't tried to pay Hogwarts back for an entire school year," Phineas Nigellus Black countered, "nor have you made any attempt to discuss when and how you were expected to do so. Did you honestly believe I was going to let you pay me back whenever you felt like it on my good heart? It could have taken you a century, as far as I knew."

… If Harry was being honest a second, that was exactly what he had hoped would happen and it was only the fact he was still stuck here that had stopped him from running away without paying anything.

Still, it was so unfair Harry wanted to scream. He had paid the man back as soon as he had been able to. Shouldn't that be enough? More than that, that money had first been given to him and now the man wanted to earn money on his back?

"You have until the first of September of the next year to finish paying Hogwarts back," he concluded. "Is that understood?"

Harry gritted his teeth.

"Is that understood?" he repeated.

"… Yes."

"Yes, sir."

"There's no need to call me 'sir', Headmaster."