This story is a charity commission for John Smith, who specifically wanted a story where Theseus and Newt go back in time to interact with a younger Newt during his school years. Granted, time-travel of that sort isn't technically possible, but for the purpose of the story I've studied the rules and potential consequences of time turners and merged them with the given prompt to make this story as realistic as possible. Some context was drawn from The Cursed Child, in which Albus Potter and Scorpius Malfoy demonstrated how one might meddle with time.

Disclaimer: Neocolai does not own Fantastic Beasts or anything related to J.K. Rowling's work. Credit for this story's inspiration goes to John Smith, who talked through the idea with me and helped create this lovely piece of fluff and angst.

.

.

.

The old classroom, with its scarred desks and wooden floor worn down by hundreds of pairs of black shoes, was exactly like Theseus remembered. A film of chalk dust sifted past the windows, drifting down to coat every surface. Patches of wan sunlight, scattered amidst the heavy clouds of autumn, illuminated shelves that were stuffed with tattered second-hand books and empty cages. There were still notes on the blackboards from the morning's class.

Transfiguration had always been Newt's most troublesome subject, as Theseus recalled from his brother's O.W.L.S. It was ironic that Dumbledore had asked them to meet here instead of the comfortable simplicity of his own classroom. One more way to put Newt ill at ease (as if the company of a certain late Headmaster's portrait wasn't enough).

"I will have it known that I disagree with this reprehensible plan," the portrait of Headmaster Phineas Nigellus Black objected. Had been objecting since Theseus entered the room. "Not only is it dangerous and corruptive to past generations; it is a mockery of the history which spawned this era. We all live by our mistakes. I think it is a fool who meddles with his own past."

"Yes, thank you, Professor Black," Dumbledore said tolerantly, ignoring the portrait's bushy-browed scowl. "I am well aware of the risks, as is young Mister Scamander."

"Posh! Mister Scamander couldn't find his own classroom half the time. I still believe this errand will come to ruin."

"Theseus," Dumbledore greeted with a grievous sigh, nodding to a chair. "Late Headmaster Black, as I'm sure you know. I apologize for the sudden notice and the secrecy."

"It wasn't an illuminating report," Theseus agreed vaguely, choosing to stand beside one of the tables. He nodded acknowledgment to his brother, who was slouched in a chair across from him, his suitable wool coat exchanged for that outrageous blue piece that warranted the attention of every auror serving under Grindelwald. Newt looked as reluctant as Theseus to be conversing with the least favorite Headmaster of their time.

"The Ministry might have lifted some of my restrictions, but I'm still under close watch," Dumbledore explained. "Some things are too dangerous to be leaked to Grindelwald's followers."

"Which is why you called for Newt and myself," Theseus said carefully. In part it made sense; Newt had been a favorite lately for Dumbledore's little errands. This was the first time Theseus had been invited into their co-conspiracy.

"Actually, he asked me," Newt piped in. As always he responded passively, restrictive with his wording, but the adamancy in his voice leaked through. "Dumbledore wants me to undertake this mission."

"It's imperative against Grindelwald," Dumbledore said, beginning to pace idly, a silver chain swinging from his fist. "I need a certain manuscript from the restricted section of Hogwart's library. The book was lost for some time and several pages were torn out - a careless student, I don't doubt. Without those pages I cannot hope to destroy this."

He held out his palm, presenting a key-like pendant on a slender chain. Eyeing it critically, Theseus shrugged. "A family artifact?"

"Of a sort," Dumbledore conceded. "More precisely, a token: an oath between Grindelwald and myself that we would never challenge one another in combat."

"A blood pact," Theseus realized, stiffening against the edge of the table. "It's absolutely unbreakable. That's why you sent Newt to apprehend him."

Crossly he glanced at his brother, reminded once again of the peril Dumbledore had placed him in by sending him to find Credence. Alone. We still have to talk about that, he communicated with a stern glare.

Shifting uncomfortably, Newt elaborated, "Dumbledore thinks that the lost pages of the manuscript could help him dismantle his part of the pact, without harm to either participant. He wants me to find them."

"So what then - search the library?" Theseus challenged. "Any secretary could do that."

"The pages were lost long ago," Dumbledore said. "I need someone to find them before nineteen-eleven."

Appalled, Theseus stressed, "Nineteen-eleven? The year?" He looked between the professor and Newt and huffed. "You're jesting. You're proposing time travel? It's impossible."

"On the contrary, time-turners are a tested and proven convenience often used by the Ministry itself," Dumbledore said pointedly.

"For imperative business and diplomatic courtesy only," Theseus corrected. "You can't just play around with time. The consequences are unthinkable! You can't be seen, you can't meddle outside of your time sphere, and you cannot correct a wrong."

A deep matter he pondered on often, for the inability to retrieve the lost plagued him night and day. But the truth remained. For the sake of the future, one dare not alter the past.

"I'm fully aware of the procedures, Mister Scamander," Dumbledore said. "However, I'm not asking Newt to jeopardize time. All I need is a copy of Blood Bonds and Boundaries. Professor Black and I have written a letter to be given to the current headmaster. The book was accounted for early in the semester, and has since been removed from its place. Newt will go undercover for whatever time frame is necessary to find the lost manuscript, retrieve the pages, and leave before the term is over."

Aghast, Theseus laughed derisively. "Before the term is over? You must think that you have all of time at your disposal! The time-turner only permits its user to stay for five hours in any given period. Any longer of a stay could jeopardize the past and the present."

"Yes, but improvements to this model have managed to stabilize the time sphere," Newt said, picking intently at a strip of leather peeling from his case. "Interaction in a similar timeline is possible for extended periods, so long as nothing imperative is changed."

Shrewdly Theseus regarded his brother. "You've tested it," he realized. Hissing between his teeth, he shook his head. "You've already tested it and you didn't even consult me - "

"I knew what you would say," Newt interrupted. "I know the risks, Theseus. If destroying the blood pact can stop Grindelwald - "

"You don't get it, do you?" Theseus stressed. "You think that because Dumbledore proposes some grand scheme then it's perfectly justifiable for you to break the rules? How many times do you think you can get away with it before the Ministry deems you too unruly to handle? Do you think I want to see you in Azkaban?"

The mere mention of the unspeakable prison made Newt flinch. Good. Maybe he would think more carefully about his exploits in the future. Sighing, Theseus leaned back against his perch. When would his brother learn that he wasn't obligated to answer to every whim of his favorite professor? Dumbledore could find another messenger. He couldn't replace Newt.

"If you need the papers so badly, why don't you fetch them yourself?" Theseus challenged Dumbledore.

The professor had the grace to look uncomfortable. "I'm already a professor in my given position. Two adults in the same timeline, investigating the same school? The effects would be dynamic. Newt is young; his timeline is still flexible. As long as he's careful, it shouldn't affect him."

"And if you're wrong?" Theseus said thinly. Darkly. A strip of ice over black water, threatening the ambler to tread carefully.

"I've already accepted the position," Newt said quietly.

Swinging around, Theseus fixed him with an agitated glare. "What?"

"I've spoken with the Headmaster of the time," Newt said. "We've been corresponding back and forth; testing the time-turner for inconsistencies. He's given me a position for the Spring Term. Pest control - nothing complex. I borrowed a few nifflers to infest the kitchens."

Gaping, Theseus looked rapidly between his brother and the portrait of Phineas Black. "You infested Hogwarts with nifflers?"

"They're harmless!" Newt hastily defended. "A bit mischievous, granted, but only when shiny objects are involved."

"Nifflers. In the kitchen." Scoffing, Theseus nodded towards a copy of the Daily Prophet. "Should I be checking the news columns for a historical article?"

"Time is still fluctuating," Newt said solemnly. "It takes a while to catch up."

Theseus shrugged. "It's been over a decade since nineteen-eleven."

"Nineteen-ten," Newt corrected, "And I'm not finished there yet. Aside from the nifflers, nothing has been altered."

"Nifflers are hardly a newsworthy article," Dumbledore added.

"I'll be hired as a pest controller to round them up," Newt continued. "It will take me some time, of course, which will give me plenty of opportunity to research the library."

"When you're not looking after your brood and crawling under pantry shelves," Theseus said satirically. "How much spare time do you think you'll have?"

Though he flushed, Newt held his ground. "Enough," he said elusively. "I have until the end of term."

"It's preposterous. You're insane," Theseus said directly to Dumbledore. "It'll never work."

"At least I gave you fair warning this time," Newt said breezily.

The cool authority in his voice was too much. The upstart brat thought he knew everything, didn't he? "And what makes you think you're going unsupervised?" Theseus said icily.

Ah, the grim set to the jaw that signified a sullen Newt. He knew the implications, all right. "I can do very well on my own, Theseus."

"With a stolen time-turner, no doubt." Rising from the table, Theseus ambled towards his brother, focusing his argument on Dumbledore's nonfamilial reasoning. "Stolen Ministry property, which makes this Ministry business. Unless you want an official report and an investigation, I suggest you provide Mister Scamander with a suitable escort; both to assist with his research and to see that the timeline is minimally influenced. With a niffler infestation in place, the Ministry will require a Health and Safety Inspection to ensure the good health of the students."

"I believe young Theseus Scamander is an intern at the Ministry at this time," Dumbledore said, his eyes glinting with cheek. "It would be conservative of both time and resources to send a novice to do the legwork."

"Young Mister Scamander would already need to be out of the office," Theseus warned.

"On a diplomatic tour," Dumbledore said breezily. "In Paris, consulting with the Ministère des Affaires Magiques de la France on ways to improve the efficiency and communication of their paperwork division."

"I don't remember that either," Theseus said flatly.

"Time is still fluctuating," Dumbledore assured. "You haven't been to Paris yet, after all. Certain events take longer to catch up; that should give you time to correct any mistakes."

"Relatively speaking," Newt interjected. "It's still a linear timestream; we can't re-enter the timeline once we've become imprinted on it."

"Imagine twenty-odd Newt Scamanders running through Hogwarts in synchronization," Dumbledore mused.

The thought was terrifying.

"When do we leave?" Theseus said resignedly. For Newt would not be travelling on his own. Not this time, with so much at stake.

From the smothered delight in Dumbledore's eyes, he had been planning on Theseus' participation all the while. A pox on the man.

"As soon as your position is assured," the professor answered. "We'll have official papers drawn up and delivered to the Headmaster. Professor Black has dictated the letters which will convince his younger self of the necessity of your mission. You won't be questioned."

"In and out, no trouble," Theseus said dourly. Newt was determinedly avoiding his eyes. You can't ignore me that easily, Newton, Theseus vowed. As soon as the professor leaves the room, you and I are going to have a little chat.

His first assignment as a proper inspector from the Ministry would be documenting how many creatures Newt intended to afflict upon his old school grounds. There had to be a limit as to how many pilferers were permitted to roam unfettered in a public building. Knowing Newt, he'd let the scruffy, filthy vermin breed inside of the castle!

Regardless of Dumbledore's manipulation, Theseus accepted that he had no choice but to accompany Newt on this nefarious quest. Someone had to keep his brother's wiley pests under control.

And bring the Pest himself back home again.

.

.

.

*Note - The book Dumbledore mentioned (Blood Bonds and Boundaries) is absolutely noncanon. Sadly, there is little to be said about books in the Restricted Section of the library and this author had to create something for the script.