It was by far the weirdest thing they'd ever been through… The year is 2021 and James Potter and Fred Weasley, now notorious sixth-years, are about to get pulled into a crazy final month at Hogwarts, as they unexpectedly switch places with their namesakes after an experiment gone awry.

DISCLAIMER: I don't own any of Harry Potter or his offspring.

Chapter 1: Switch!

"Ow!" 17-year-old James Potter exclaimed as he got an elbow in the side from his cousin. "Fred, stop it, you're hammering me!"

"Oh, sorry, Jay," 17-year-old Fred Weasley replied, swiftly moving so that Jay could advance and see what was going on. "Here, you think it's supposed to do that?"

"Do what?" Jay asked, eyeing the mirror sceptically. "That swirly thing?"

"Oh, move over, Jay, I can't see it any more," Fred said impatiently, shoving him aside. "Yeah, hey, look, I can see Dad and Uncle Fred. They're… Merlin, I think that's the early version of the Whizbangs! Jay, you have to see this, this is so completely retro!"

"You think that's retro," Jay scoffed. "Wait until you see my grandfather's era."

"Oh, Merlin, that's not retro, that's vintage. I mean, that would've been what, 1970s?" Fred studied the swirling picture curiously. "We are going to be –"

"Millionaires in our own rights," Jay finished. "My dad's family is old money, remember? Uncle George made his millions with the shop, Teddy's taking over for Ollivander, and we all know he's got a monopoly on the wand market…"

"And we are going to be the top inventors in the world!" Fred crowed, just as there came an explosion.

"Potter! Weasley!"

The two boys got to their feet, looking at each other in confusion before Professor McGonagall came striding out into the courtyard.

"Professor McGonagall!" the boys both chorused in innocent voices.

"Calamity," McGonagall declared, grabbing both boys by their ears, "runs in your family, apparently. Your fathers, your uncles, your grandfathers – yes, boys, Arthur Weasley was a troublemaker in his day! – not to mention you two! To the hospital wing! What were you concocting now?"

"Who the hell are you?" James hissed at the red-haired boy sitting on the bed across from him.

"Your partner-in-crime, apparently, and a relation of some sort," the boy replied cheerily. "Fred Weasley, pleased to make your acquaintance. You must be James Potter. You're clearly not Harry, since you don't have the scar. Quite the reputation you've got there, Prongs."

"Weasley?" James asked. "Any relation to Septimus?"

"Yep, that'd be my grandfather. Paternal."

"He's a cousin of some kind, a few times removed, I think, so we're pretty distant in relation. What's going on, you think?"

"I dunno," Fred shrugged, looking around the ward. "Hogwarts looks all the same. Last thing I remember before the explosion was me and George – that's my twin – plotting our glorious departure. We were testing out the Whizbangs before the execution, and a dud exploded in our faces. What about you?"

"I was coming out of…" James stopped. He and Sirius and Peter had been exiting the Whomping Willow after a full moon. Peter hadn't held the knot long enough and James had gotten smashed by a branch. "A passage, I was coming out of a passage and got thrashed."

"Whomping Willow?" Fred asked knowingly. "Yeah, we know about the secret passage under there and how it was Lupin's little hidey-hole on full moon."

"Hold your tongue, Mr Weasley," Madame Pomfrey said briskly as she entered. "Lupin hasn't had a hair of a symptom since that night, let's not tempt fate. As if the scar wasn't enough of a reminder of it, he doesn't need his cousin belittling the experience. I'd like to see you live through a night like that."

Both boys frowned at her at that declaration, and then the doors to the hospital wing opened and a young man in his early twenties came in, his sandy brown hair sporting blue and purple frosted tips. A deep, ugly set of parallel scars that crossed from his right temple across to his left jawbone marred his face, though he had a grin on his face, an almost patient expression in his voice as he said, "So, Jay? What's the damage this time?"

He looked like Remus, James thought in surprise, even as the young man took his wand from his hand and inspected it. Then his heart stopped as the man's face went suspicious.

"Whose wand is this?" he asked, running his own wand over it with a look of deep concentration.

"Mine," James replied uncertainly. "My parents bought it at Ollivander's almost seven years ago. You were there." It was true. Remus and his parents had been in Ollivander's at the same time as them.

"Jay, how many times have I repaired your wand for you? Fifty? A hundred? I know your wand, and this isn't it." He held it in his open hand, pointing his own wand at it. "Declare your original owner."

An ethereal voice floated out into the room. "James Potter."

"See?" James said defensively, reaching for his wand.

"Your structure, core and registration date."

"Mahogany and dragon heartstring. Registered August 22, 1971."

"197– " the man sputtered, then the light seemed to go on. "Oh, Merlin, you're not him. You're…" He stared at him for a moment. "Oh, that's not good." He whirled around to face Fred, who looked as utterly lost as himself. "Fred, what did you do?"

"I… don't know," Fred said indignantly. "I don't think you've got the right Fred, either, I'll tell you that right now. And somehow I don't think you're the Lupin I know."

"I don't know, what year do you think it is?"

"Well, it's 1996, innit?"

"It's 1978," James spoke up hesitantly.

"You're both wrong," Whoever Lupin said, rubbing his temples. "Try 2021. Merlin, this is such great timing… so where's our boys?"

Both of them shrugged and shook their heads, just another teenage boy who looked similar to James entered. This one looked about fifteen. "So, Jay, you blew up the courtyard. Nice job, Filch is furious."

"You Potters seem to like blowing up Hogwarts," Lupin said semi-jokingly.

"Well, Dad didn't exactly blow up Hogwarts, Teddy," the boy replied. "More like, he caused it to go up in flames."

"When did that happen?" Fred asked without thinking.

The boy stared at him. "The battle of Hogwarts, dolt? The final battle? The big, bloody, fiery, lots-of-people-dying battle that finished the Second Dark War? Merlin, you must've hit your head pretty hard."

"Any way," Teddy said briskly, handing James back his wand after a brief, ugly silence. "I've got to get back to Diagon Alley, I don't need to repair any wands here..."

"Oh, before you go, can you repair the nick in mine?" the other boy asked, holding out his wand. "It's not like I'm Jay, Teddy, I don't damage my wand every other week."

"What happened to it, Al? You're usually pretty good with your wand."

"Bludger. Broke my arm guarding my wand, if that hits the sympathy chord."

"I really ought to start charging you two."

"You've already got access to our vault, remember?" Al laughed. "Dad gave you a key when you turned 17."

"How about you tell him about James and I don't charge you?"

"I'm not telling him Jay blew up the school again! I told him last time, it's Lily's turn. Besides, she's Daddy's little Seeker princess, he won't get so mad at her, he's been on a short fuse lately."

"I'm not telling him!" came the indignant exclamation from a younger-still red-haired girl of about thirteen who walked in.

"You blew up the courtyard," came the semi-disbelieving, semi-amused, semi-exasperated, semi-furious statement from the dark-haired Auror who paced in front of James and Fred, who were both sitting silently in chairs.

"You blew up," the red-haired man on the Auror's other side repeated, "the damn courtyard."

"What the hell for?" the Auror finished. "You know how many people you could've endangered, James? Frederick? How many students you could've injured or killed or worse? How many things could've gone wrong –"

"Something did go wrong, Harry," Fred spoke up quietly. "You're yelling at the wrong Fred and James."

"How many Fred Weasleys and James Potters do you figure there are around here?" the red-haired man asked.

"I don't know, George, but somehow the guys you think you're talking to have been exchanged with, well, us. We're from the past, ask whoever the hell the wand guy in the hospital wing was."

"Wait, so…" George said suddenly, staring at the two teenagers. Fred nodded.

"Great," Harry muttered, running a hand through his rumpled hair. "Great. This would happen, he would wreak havoc on the entirety of the damn family on the brink of a war…"

"Harry, somehow I don't think Fred and Jay meant for this to happen," George pointed out logically.

"Still… they had to have been fiddling with a time device – as if we haven't told them a thousand times the dangers of meddling with time!"

There was a brief explosion outside Hogwarts grounds just then, and terrified screams drifting through the air. Casting a glance outside the window, both Harry and George paled.

Outside, in the evening sky, a smoky Dark Mark was illuminating the sky above Hogsmeade.

"Jamie, my boy, the tree must've squashed you good," Sirius Black declared as he sat back and looked at his best friend, who seemed disoriented and horribly confused. "Cracked your skull again, maybe?"

"Nah, it takes you to crack his skull, Seer," Remus Lupin commented, glancing nervously at the Dark Mark outside again.

"Wonder who did that?" Peter Pettigrew asked fearfully.

"Dunno, Peter, maybe a Death-Eater," Sirius said casually. "You think we can risk heading out again?"

"We should at least try," Remus said doubtfully. "I don't want to be around if and when the Death-Eaters come charging in. And besides, you guys have missed a whole day of classes."

"Yeah, all right," Sirius conceded, catching James by the arm. "Up you go then, Potter. Maybe we should take you to Madame Pomfrey. Peter, go ahead."

James shook his head, almost as though to clear the cobwebs from it, and muttered, "What the hell is going on?"

Peter came back in a few moments later. "Guys, the passage is blocked. It's collapsed."

"You mean we're trapped in here?"

"Yeah, I guess."

"Listen to me very carefully, all of you," Harry said authoritatively as the Potter-Weasley family's children were all gathered in the headmistress' office. "You are all to stay right here. That includes you two," he added to James and Fred.

"Well, I'm not staying here," Teddy spoke up with certainty, leaning back against the wall with Victoire in his arm. His hair was now black with streaks of fire engine red, falling down into his eyes with a careless casualness that reminded James very strongly of Remus. "I'm going with you guys."

"Well, I know I can't make you stay," Harry replied. "You're half Tonks and a quarter Black."

"Not to mention of age."

"That too. Al, Rose, you two are in charge," George ordered. The two fourth-years, both of whom had Gryffindor prefect badges, oddly enough, nodded.

"Hopefully we won't be too long," Ginny said with a worried glance at Harry.

"I'm going to find our James, kill him, and then find the bastard who sent up the Dark Mark," Harry muttered, eyes snapping emerald fire.

"Harry, watch your mouth," Ginny said automatically.

"So where were you two when this all took place?" George asked the two teens.

"Well, we were in that storage room testing Whizbangs…" Fred said.

"When the one dud exploded in your face?" George asked.

"Yeah, that's the last thing I remember before the courtyard," Fred replied.

"Katie, Ron, Hermione, Bill, Fleur," George said briskly as he started heading out the door. The named people followed.

"What about you?" Harry asked James.

James hesitated. "Passage," he said finally. We were in a passage."

"Oh, Merlin, that's helpful," Harry growled. "Which passage?"

"The one nobody's supposed to know about," James said evasively.

"The…" Harry swore continuously under his breath as he tried not to curse James. "Are you telling me that you were in the Whomping Willow passage last you remember?"

James nodded, getting the idea this was not a good thing.

"On a full moon?"

"Coming out of one," James replied quietly. "Peter didn't hold the knob long enough. The tree pile-drove me back into the passage."

"That's impossible," Teddy spoke up now. "Jay can't possibly be in the Whomping Willow passage."

"Why not?" 13-year-old Alyssa, George's middle child, asked timidly.

"Because I destroyed it sixth year, remember?" Teddy snapped. "The whole passageway's collapsed from the tree clear to the Shack."

"Teddy…" Victoire warned, putting a calming hand on his arm.

"Ginny, Teddy, Victoire, let's go."

"James," Sirius said again, as his best friend got to his feet shakily and headed out of the room momentarily. "Merlin, what is with him now?" He and Remus, reluctantly followed by Peter, trailed their friend out into the hallway.

"Fred," James was saying into a weird black contraption. "Fred, you there?"

"Yeah," came a crackling voice in response. "You on the radio?"

"Yeah, at least these are still working."

"Where are you, Jay?"

"In an extremely weird position."

"You got people thinking you're the other James Potter, too? I've got Dad at 17 here."

"All right, we're both in the extremely weird position. Where are you? You still at Hogwarts?"

"Yeah, we're just off Charms corridor in a closet. Door seems to be stuck and you know we can't blast it off."

"I'm trapped in the Shrieking Shack."

"Excellent. You can't get out, can you? The passage's been destroyed ever since Teddy's weird full moon thing and the house is impenetrable."

"Nope. And there's a Dark Mark floating in the sky above Hogsmeade. If you're at all interested."

"Dark Mark as in Death-Eater Dark Mark?"

"You got it."

"Did we do that?"

"I don't know."

"Jay, our dads are going to kill us."


James went to put away the radio when another voice came echoing out. "James Sirius Potter!"

James blanched and pulled it back out. "Hey, Uncle George…"

"You are going to be damn lucky to see your 17th birthday, Jay, once your father's through with you."

"Yessir." Jay figured it wasn't the best time to remind his uncle that he had already turned 17 three months ago.

"Where the hell are you?"

"In the Shrieking Shack."



"Damn it. All right, your parents, Granddad and Nan and Teddy and Victoire are on their way. They'll have to try and blast it clear. Stay put."


"You're a dead man, Potter."

"Yessir." James carefully put away his radio again and turned to look at the three teenagers staring at him. "I'm a dead man. You heard the guy. On the plus, we should be out soon."

"Who the hell are you?" Sirius asked.

"I would be…" James hesitated. "Jay Potter. James'… grandson."

"Grandson?" Remus repeated.

"Yeah. Well, my name's really James, but I don't get called that unless I'm being yelled at. Which is quite a lot, actually…"

"James and who?" Sirius asked curiously, cocking his head at the teen. "He ain't going out with anybody."

"James and Lily, coincidently my sister's name," Jay replied uncertainly.

"Lily?" Remus asked in surprise.

"Evans?" Sirius added incredulously.

"I guess. I don't know her maiden name."

"Merlin, hell really does freeze over," Sirius muttered.

"Hmm," Remus said in astonishment. "That's intriguing. When was your father born?"

"July 1980," Jay said. "Why, what year do you think it is?"

"That's two years from now," Remus mused.

"No, that's 41 years ago," Jay corrected.

"Hmm…" Sirius pondered the math for a moment. "So it's June 1978 now. July 1980 is… 25 months away. Take away nine for pregnancy…"

"So in the next 16 months, less than a year and a half," Remus calculated, "James managed to freeze hell, ask Lily out, get her to accept, marry her and impregnate her. Impressive."

"I dunno," Jay shrugged. "Not like I ever met the guy to ask. Dad didn't even meet the guy, not really." When Sirius, Remus and Peter all looked at him sharply, he explained, "Grandfather and Grandmother Potter have been dead for 40 years. Ever since my dad was a year old. Voldemort killed them." He sighed and pulled out his wand from his pocket, examining it morosely. "Damn it. I cracked it again." He looked up momentarily. "I tend to break my wand a lot. Aw, well, Teddy'll fix it once he gets here. Perk of having a godbrother who's a wandmaker."

There was a brief boom downstairs and a crash and splintering of wood.

"James!" came an angry roar.

"Up here, Dad!" Jay called. "Is Teddy with you?"

"I'm not fixing your damn wand right now, Jay!"

"But you will, right?" Jay called hopefully. "Eventually?"

"You and Teddy can negotiate once we're out of here," came the voice of a fairly young man who appeared at the head of the stairs. It was easy to see his parentage: James' appearance, but Lily's eyes. "Damn. I was hoping that hadn't happened." He delivered a swift blow upside Jay's head. "Haven't I warned you about fiddling with time devices?"

"This coming from the guy who went running around Hogwarts with a Time-Turner!" Jay yelped, rubbing the back of his head.

"That was a matter of life and death, and it was a one-time thing. And, it was Aunt Hermione's Time-Turner." He turned around when the rest of the group caught up. The youngest man in the group, who didn't look any older than his early twenties with black hair and red chunks running through it, hair falling into his blue eyes with a badly-scarred face, stopped dead in his tracks upon sight of the Marauders. He crossed his arms on the railing, leaning forward.

"Well, this is interesting," he commented, though his stunned eyes were locked in a gaze with Remus, who seemed quite shocked at this boy who could almost pass for himself. "This is almost as interesting as the hospital wing with the doppelgangers."

"This is not interesting, Teddy. This is serious."

"Very serious," the young man agreed. "But interesting all the same."

"Merlin, you sound like your mother when you talk like that."

"I know. Grandmum points that out all the time."

"You like causing utter mayhem, don't you?" Al laughed as the adults all returned, hauling Jay and Fred with them, along with the teenage George and the other Marauders.

"Chaos, Al. It's uncontrolled chaos that we cause," Jay replied with a slight grin.

"I'm going to cause loss of life and limb if you two don't shut it and soon," Harry and George growled in unison.

"All of you, stay here," Harry ordered. "Al, Rose, you two are still in charge."

"But we're oldest!" Jay and Fred exclaimed indignantly.

"Yeah, but Al and Rose didn't blow up the damn courtyard and screw with time devices," Harry replied tersely.

"… prefects…" Jay muttered under his breath, glowering momentarily at his brother.

"But Jay and I are of age!" Fred protested.

"If you feel like being helpful, try undoing whatever you did," George snapped as the adults all left.

"What did you do?" Alyssa asked as the rest of the underage cousins gathered together.

"Not entirely sure, to tell truth," Fred replied to his sister.

"Shall we reverse-engineer?" Jay asked, gazing gloomily at his cracked wand. "Or at least you will."

The door opened just then, and Teddy strode back in. "Give me your wand," he said with a sigh. Jay grinned and passed it over.

"Thank you, Teddy," he said as Teddy repaired it quickly. "You're the best godbrother in the world."

"Your brown-nosing ceased to work when you were 11, Jay," Teddy said dryly, though the slightest hint of an affectionate smile teased at his lips as he passed back the wand. Then he left again, closing the door behind him.