Chapter Text
The golden rule of 12 Grimmauld Place was remarkably simple, carved into the unspoken laws of the house alongside 'don’t look directly at the house-elf heads' and 'keep your voice down near the velvet curtains in the hall'.
The rule was this: If a door is locked, and that door belongs to Harry Potter’s private study, you do not enter it.
Naturally, James Sirius Potter took that as a formal, written invitation.
"James, I swear to Merlin, if Uncle Harry catches us, he’s going to sentence us to hard labor at the Weasleys' Wizard Wheezes inventory warehouse," Fred Weasley II muttered. Despite his words, his actions completely betrayed his compliance. He was currently crouched on one knee, his wand jammed precariously into the heavy bronze keyhole of the mahogany door, brow furrowed in intense concentration. "And let me tell you, counting U-No-Poo boxes for fourteen hours straight is a special kind of hell."
"Dad’s at an Auror conference in Paris until Friday," James scoffed, leaning against the damp, peeling wallpaper of the third-floor corridor with an easy, crooked grin. He ran a hand through his untidy, jet-black hair, messing it up further in a habit that was practically genetic. "He’s probably eating croissants and talking about international smuggling rings. He’s not going to know. Besides, he left his old school trunk up here. The one from his Hogwarts days. Don't tell me you aren't curious about what he kept from the nineties."
"I am curious," a voice dropped from the shadows behind them, heavy and dripping with sheer, unadulterated exhaustion. "I'm also twenty-three, a literal Auror trainee, and currently responsible for making sure you two teenage menaces don't accidentally blow up a historical landmark."
Teddy Lupin stepped into the dim, flickering candlelight of the narrow hallway. His hair, usually a vibrant, eye-watering shade of electric turquoise, was currently a stressed, muddy shade of mouse-brown. He stood with his arms crossed over his chest, his Auror-in-training robes slightly rumpled, looking every bit the responsible adult he was desperately trying—and failing—to be.
"Teddy! Mate! Guardian angel! Anchor of my soul!" James cheered, throwing a heavy arm around his godfather's son, completely unfazed by the glare directed at him. "We’re not doing anything illegal. We’re just doing some... immersive historical research. For our N.E.W.T.s. You love education."
"You've been suspended from the Gryffindor Quidditch team twice this term, Jamie. You don't care about education," Teddy sighed, pinching the bridge of his nose where a stress headache was rapidly forming. "Fred, stop casting Alohomora. The Ministry uses specialized wards on Auror residences—"
Click.
The heavy iron lock gave a satisfying, deep snap. Fred grinned upward, his amber eyes flashing with triumph as he shoved his wand back into his pocket. "Research is officially open, boys."
Before Teddy could physically tackle them out of the corridor, James darted inside the room.
The study smelled strongly of old parchment, ozone, wet wool, and dried floo powder. It was a cluttered haven of magical artifacts. Sneakoscopes spun lazily on the bookshelves, a Foe-Glass hung crookedly against the far wall, and stacks of top-secret Ministry files were piled dangerously high on a massive oak desk. But it wasn't the files that caught James’s attention. It was a small, velvet-lined mahogany box sitting right on top of his father's old school trunk, left slightly ajar.
"Look at this," James whispered, his voice dropping its bravado as he approached the desk.
"James, don't touch anything," Teddy warned, stepping into the room with his hand resting instinctively on his wand holster. The magical ambient hum in the room was making the hairs on his arms stand up. "We're leaving. Right now."
But James was already lifting the lid of the box. Inside lay an hourglass, but it looked nothing like the delicate gold Time-Turners Hermione Granger had used in her youth. This one was encased in a heavy, dark iron cage, wrapped in intricate, glowing silver runes. The sand inside wasn't golden; it shifted from a deep, blood-red to a dark, midnight black, swirling like a miniature galaxy trapped in glass.
"Bloody hell," Fred muttered, leaning over James’s shoulder. "That looks like something out of the Department of Mysteries."
"It is," Teddy said, his voice dropping all pretense of joking. His heart hammered violently against his ribs. He recognized those specific, heavy containment runes. His Auror training kicked in, a cold spike of panic overriding his exhaustion. "James, drop it. Do not touch the iron casing. That’s a Chronos Anchor. It’s a prototype for localized time anomalies. It’s highly unstable."
"I'm just looking—"
"James, seriously, put it back!" Fred reached out, suddenly sharing Teddy's panic, and grabbed James's wrist to force his hand away.
It was a split-second mistake. James flinched back from Fred’s sudden grip, his fingers slipping on the smooth iron bars of the device. The heavy iron-and-glass contraption tumbled from his hand.
Time seemed to slow to a horrific, agonizing crawl. Teddy lunged across the desk, his hand outstretched, his fingers brushing the cold metal casing just as it struck the hard stone floor.
CRACK.
It didn’t shatter like glass. It exploded like a localized supernova.
A blinding, violent crimson light swallowed the room, ripping the air straight from their lungs. The sound was deafening—a roar like a thousand crashing trains mixed with the ticking of a million grandfather clocks. The floor beneath them vanished entirely. James tried to scream, but the vacuum of the vortex stole the sound. They fell backward into a roaring abyss of spinning colors, suffocating darkness, and the terrifying sensation of being pulled apart and stitched back together, second by second, year by year.
The transition from the void back to reality was violent and sudden.
James hit a solid surface first, landing flat on his back with a groan that rattled his teeth and knocked every molecule of oxygen out of his lungs. A second later, Fred landed squarely on top of his stomach with a muffled "Oof!" and a crack of limbs. Teddy, ever the clumsy metamorphmagus when startled, crashed into a nearby wooden table, sending a cascade of silver plates and heavy metal chalices clattering loudly across a stone floor.
"Ugh... Fred, get your bloody elbow out of my ribcage," James wheezed, blinking back tears of stinging pain. He shoved his cousin off him, rubbing his aching chest and coughing as a massive cloud of dust and white smoke swirled around them.
The air was instantly different. It didn't smell like the damp, dusty, rain-soaked wood of Grimmauld Place. It smelled like pumpkin juice, roasted potatoes, woodsmoke, and old, enchanted stone.
"Where are we?" Fred groaned, sitting up and picking a stray piece of tinsel and what looked like mashed potato out of his hair. He looked around, his jaw slowly dropping as the smoke began to clear. "Uh. Jamie? Look up."
James looked up.
They weren't in the attic anymore. They were standing at the very front of a massive, cavernous room. Above them, a familiar, sprawling enchanted ceiling showed a stormy twilight sky filled with dark, rolling clouds. Four long house tables stretched out across the hall, packed with hundreds of students clad in black Hogwarts robes.
Every single one of them was staring at the three boys in dead, paralyzed, pin-drop silence.
James slowly stood up, his knees shaking slightly. He looked down at himself. He was wearing muggle jeans and a faded Holyhead Harpies hoodie. Fred was in a bright orange Chudley Cannons sweater. Teddy was in his dark Ministry robes. They looked completely alien.
At the staff table, which was raised on a platform directly behind them, a remarkably younger, dark-haired Professor McGonagall had dropped her heavy silver goblet of pumpkin juice. It clattered loudly against the table, the liquid spilling over the velvet runner, but she didn't seem to notice. Her eyes were wide behind her square spectacles, her hand pressed hard against her throat.
Next to her, Headmaster Albus Dumbledore—very much alive, with a pristine, unburnt right hand and a vibrant plum-colored robe—was slowly rising from his golden, throne-like chair. His piercing blue eyes flashed with an intense, calculated sharpness behind his half-moon spectacles, the usual twinkle completely replaced by profound calculation.
James swallowed hard, the silence stretching out until it felt suffocating. He turned his head slowly, his eyes darting toward the Gryffindor table to his left.
Sitting near the middle of the table was a boy.
The boy had untidy, jet-black hair that stuck up wildly at the back. He wore crooked, wire-rimmed glasses, and his Gryffindor tie was loosened significantly at the collar, a smirk frozen on his face. He was currently staring at James with his mouth open, holding a half-eaten chicken wing directly in front of his face, completely frozen in time.
James Sirius Potter looked at the teenage version of his grandfather. The resemblance was horrifyingly exact—right down to the shape of the jawline and the stubborn, untamable cowlick at the crown of his head.
Next to the teenage James Potter sat a handsome boy with elegant, jaw-length black hair that fell into his eyes with effortless, aristocratic grace. He looked like he’d just seen a ghost, his pale skin going entirely translucent. Further down, a quiet, pale boy with faint, silvery scars scoring across his cheeks had let his fork drop heavily onto his plate, his eyes wide with a mixture of analytical fear and shock.
James Sirius turned his head slowly to Teddy, whose hair had completely lost its brown color and had flashed a panicked, blinding, snow-white.
"Uh," James squeaked, his usual infinite bravado vanishing completely into thin air under the weight of five hundred pairs of eyes. He cleared his throat, offering a weak, trembling wave. "Happy Halloween?"
"What in the name of Merlin..." muttered a voice from the Gryffindor table. It was the handsome, dark-haired boy—Sirius Black. He looked between James Sirius and the teenage James Potter beside him, his eyes darting back and forth so fast it looked like he was watching a high-speed Quidditch match. "Prongs... mate... did you have a secret twin your parents forgot to mention?"
"I... I don't think so," James Potter I whispered, finally dropping the chicken wing onto his plate. He stood up slowly, leaning his hands on the table, staring at the boy in the center of the hall who wore his exact face, his exact hair, and a weird, tight-fitting muggle garment with words printed on it. "Who the hell are you?"
Before James Sirius could open his mouth to say something incredibly stupid—which Fred could practically see happening in real-time—Teddy stepped forward, shoving both James and Fred behind his back. His Auror instincts were screaming at him. They were in the past. The lack of gray hair on Dumbledore, the presence of people who should be long dead, the historical banners hanging from the walls—it was undeniable.
"Nobody speak," Teddy commanded, his voice carrying the sharp, authoritative ring of a trained wizard, despite the fact that his hair was still a dead giveaway of his absolute terror. "Don't say a single word."
"I believe," Dumbledore’s calm, resonant voice cut through the rising murmurs of the Great Hall like a knife through butter, "that an explanation is tightly required. Restraint, if you please, students."
Dumbledore stepped down from the staff platform, his long silver beard sweeping against his belt. He walked with a slow, deliberate grace until he stood a mere three feet away from the three time-travelers. His eyes scanned them, noting the modern fabrics, the sheer terror in Teddy's posture, and finally, the striking, undeniable features of James Sirius Potter.
"Minerva," Dumbledore said softly, never breaking eye contact with Teddy. "Please escort the students back to their respective common rooms. Prefects, lead the way. Feast is concluded for the evening."
A collective groan of protest rose from the tables, heavily spearheaded by Sirius Black and a young, fiery-haired Lily Evans, who was currently staring at the newcomers with a fierce, analytical intensity.
"Headmaster, you can't be serious!" Sirius called out, leaning over the table. "That kid looks exactly like Prongs! Is Polyjuice a joke to you?"
"Now, Mr. Black," McGonagall’s sharp voice barked, her Scottish brogue snapping the hall into obedience. She had recovered her composure, though her face remained pale. "Move along. Prefects, immediately."
The Great Hall erupted into a chaotic flurry of moving benches, shuffling feet, and loud, whispered theories. James Potter I didn't want to move, his eyes locked onto James Sirius until Sirius Black practically dragged him backward by his robes, whispering furiously in his ear. Remus Lupin followed them, his eyes lingering on Teddy's white hair with a strange, lingering look of deep confusion before he was pushed out the heavy oak doors by the crowd.
Within five minutes, the Great Hall was entirely empty, save for Dumbledore, McGonagall, and the three boys standing in the center of the room.
"Well," Dumbledore said, a faint, dangerous spark of his signature amusement finally returning to his eyes. "It seems we have had a rather dramatic disruption to our Thursday dinner. May I ask your names, or would that be too much of a strain on the delicate fabric of time?"
Teddy took a deep breath, stepping forward and lowering his hands, though he kept his body tense. "Professor Dumbledore. My name is Teddy. These are my... cousins, James and Fred. We have suffered a catastrophic containment failure of a prototype Ministry device."
"A Chronos Anchor," Dumbledore stated, rather than asked. He looked down at the shattered pieces of iron and dark sand scattered around Teddy’s boots. "An experimental device. The Ministry has been playing with fire for some years regarding localized temporal manipulation. I see their efforts have yielded... chaotic results."
"We didn't mean to!" Fred blurted out, his hands held up defensively. "It was an accident! James has slippery fingers!"
"Hey! You grabbed my wrist!" James yelled back, his natural defense mechanism of arguing with his cousin kicking in despite the fact that Albus Dumbledore was staring at them.
"Silence, both of you," McGonagall snapped, stepping forward. Her eyes scanned James Sirius’s face, her expression softening for a fraction of a second into something resembling utter disbelief before hardening again. "Albus... the boy. He looks precisely like—"
"I am well aware of who he looks like, Minerva," Dumbledore said softly. He turned his gaze back to Teddy. "What year have you come from, young man?"
Teddy hesitated. The golden rule of time travel was to give away as little information as possible. But looking at Dumbledore—the man who knew everything, the man who could actually help them fix this—he knew lying was useless.
"Two thousand and twenty-six," Teddy said quietly.
McGonagall drew in a sharp, rattling breath, her hand flying to her mouth again. "Fifty years... Merlin's beard."
Dumbledore simply hummed, his expression unreadable as he stroked his silver beard. "Fifty years. A substantial leap. And I imagine, given the physical traits present in your young companion, that his presence here presents a rather severe paradox if he were to walk the corridors unmonitored."
"He can't walk the corridors!" Teddy said quickly, panic bleeding back into his voice. "If his... if the students see him up close, if they figure out who he is, the timeline could fracture. We need to go back. Immediately. Can you fix the Anchor?"
Dumbledore knelt down, his robes pooling around him on the stone floor. He reached out with his long fingers, hovering his hand over the broken iron frame and the dark, swirling sand. He closed his eyes, humming a low, tuneless melody. The silver runes on the metal flickered weakly, then died out completely, turning a dull, lifeless gray.
When Dumbledore stood back up, his face was grave.
"The magic within the device is not broken, but it is entirely spent," Dumbledore explained calmly. "It acts as a battery, you see. It used every ounce of its stored temporal energy to tear a hole in the fabric of the decades and deposit you here safely. To recharge it... that will require time. And a highly specific set of environmental transmutations."
"How long?" James Sirius asked, his voice losing its cockiness entirely. For the first time, the reality of what he had done was settling into his chest. He was stuck in the seventies. His dad wasn't an Auror here; his dad hadn't even been born yet. His grandparents were teenagers who didn't even like each other yet.
"A week, perhaps two," Dumbledore said. "The alignment of the upcoming celestial phase will assist in the tethering process. Until then, you are guests of Hogwarts."
"Guests?" McGonagall whispered furiously, stepping closer to the Headmaster. "Albus, look at him! You cannot honestly expect James Potter to sit in a classroom with a boy who shares his skull! The entire school will be in an uproar by breakfast!"
"Which is why," Dumbledore said, a slow, brilliant smile spreading across his face, "we must employ a bit of creative truths. Tell me, young James, do you happen to have a middle name?"
James Sirius blinked. "Sirius. James Sirius."
Teddy groaned loudly, burying his face in his hands. Fred let out a muffled snicker.
Dumbledore’s eyes twinkled fiercely. "Ah. Excellent. A family name, no doubt. For the duration of your stay, you will be known as Jamie and Freddie Prewett. Distant cousins of the Weasley family visiting from a private academy in Canada. And you, Teddy?"
"Lupin," Teddy said before he could stop himself.
Dumbledore’s brow twitched upward, a flicker of deep, profound sadness passing through his eyes so quickly Teddy almost thought he imagined it. "Teddy Lupin. A fine name. You shall be introduced as an assistant consultant sent by the Ministry to oversee a special project. You will stay in the staff quarters. As for your younger companions..."
"They need to be hidden," Teddy insisted.
"On the contrary," Dumbledore countered smoothly. "Hiding them creates a mystery. A mystery breeds investigation. And if there is one thing the current fifth-year Gryffindors excel at, it is investigation. No, I believe it is best to hide them in plain sight. They shall be sorted into Gryffindor temporarily. They will attend classes. They will blend in."
"Blend in?" Fred looked down at his neon orange Chudley Cannons sweater. "Professor, we look like we’re from the future. Our clothes—"
With a casual, elegant wave of his wand, Dumbledore nonverbally cast a Transfiguration spell. Instantly, James and Fred’s modern muggle clothing dissolved, replaced by standard, charcoal-gray Hogwarts school uniforms, complete with plain black ties that lacked any house colors.
"There," Dumbledore beamed. "Much more uniform. Now, Minerva, if you would be so kind as to fetch the Sorting Hat from my office? We have a rather unusual, retrospective sorting ceremony to conduct."
As McGonagall walked away, her heels clicking sharply against the stone floor while she muttered strings of complaints under her breath, James Sirius slumped against one of the long wooden tables.
"We are so dead," James whispered, staring down at his new, retro school shoes. "When my dad finds out... he's going to lock me in a vault at Gringotts."
"Your dad?" Fred laughed nervously, though his own hands were shaking. "Think about my dad. George Weasley is going to copy this technology, use it to prank himself in the nineties, and accidentally delete our entire family tree."
Teddy didn't join in on the bickering. He walked over to the grand windows of the Great Hall, looking out into the pitch-black darkness of the Hogwarts grounds. Somewhere out there, in the Gryffindor common room, his father was sitting by a fire. A sixteen-year-old Remus Lupin who hadn't lost his best friends, who hadn't spent thirteen years in lonely isolation, who hadn't met the love of his life, and who hadn't died fighting for a better world.
Teddy pressed his forehead against the cool glass, his hand clenching into a tight fist inside his pocket.
Out of time, he thought bitterly. And completely out of our minds.