A/N: This story is being written as my submission for the Jily Meets Harmony Challenge currently taking place on the Harmony Discord. The specific rules of the challenge are as follows:

Must include:

1. James/Lily and Harry/Hermione strictly.

2. James and Lily must be alive. Either by surviving Halloween, coming back to life, or their canon deaths never happening/being avoided. (Can include either Time Travel or a Canon Divergence event)

3. Sirius should also live and be free/exonerated.

4. Lily must at some point braid Hermione's hair.

5. James and Harry must at some point fly together

6. Harry cannot have a Boy Who Lived (Or Wrong Boy Who Lived) sibling.

7. No Lily or James bashing

8. The story must be written for the challenge and the challenge should be mentioned by name in an Author's Note.

Optional items to include:

-Line from James: "Are you sure you don't fancy Hermione?"

-Line from Lily: "You know, Harry is lucky to have you."

-Line from Sirius: "I'm trying to decide which pair of you lovebirds is more [ ]."

-Preferably avoids common tropes (overdone bashing, love potions etc)

We've started an FFN Community Page where we will be curating all the stories written for the challenge. A link can be found on the Community tab of my author's page.

I think that's it for the announcements except to note that while this prologue chapter is relatively short subsequent chapters will be longer. If you've read any of my other stories you should know what to expect.

Sliding Doors

"So, I think that's everything," James Potter said as authoritatively as he could manage, doing his best to mute his excitement and relief at not mucking up his first official meeting as Hogwarts Head Boy. He was supposed to look like he knew what he was doing after all.

"Remember your patrol schedule and look out for the first years when we get to Hogwarts," Lily Evans reminded the departing prefects as they filed out of their cabin.

He waited for the cabin door to slide shut before releasing the breath he wasn't aware he'd been holding.

"That went really well, I think," Lily enthused.

"Yeah, I reckon we fooled them, Lily" James joked, drawing a giggle from the Head Girl.

It had been almost nine months since Lily had begun smiling and laughing at his jokes rather than scowling and it still felt a bit odd. Utterly brilliant, but odd. He felt like a different person these days and was a bit embarrassed thinking back at the nonsense he used to get up to for fun. It was a shame it took something so awful to help sort out his priorities.

"We'll have to watch out for the Slytherin prefects though," she continued solemnly, "they really weren't pleased at a muggleborn being Head Girl were they?

"Not to mention the idiot Gryffindor that never managed to be a prefect being named Head Boy," he added ruefully.

Lily scoffed. "Well, they aren't wrong about that…you were an idiot. A big one, actually."

"Ouch," he moaned as he clutched at his heart theatrically.

"Were," she repeated, making a point to emphasize how much she hated the old James but, amazingly, appeared to be fond of the new one.

"I was really worried that they'd be awful to me but you shut them down before they could really get started. Thank you," Lily said as she bowed her head slightly and tucked a bit of hair behind her ear.

Holy shit. Lily Sodding Evans was getting embarrassed and tucking her hair behind her ear. At him!

Her gradual thawing in sixth year and the letters they'd exchanged over the summer as they talked about their upcoming duties had given him a bit of hope that his prior behavior hadn't entirely ruined his chances with the girl. Until now he'd forced himself to squash any thoughts of pushing it further until he was absolutely, positively, definitively sure that she wouldn't turn him down again. Things were looking good. Very good.

"So," Lily continued awkwardly, "we're up first for doing rounds. I suppose we should set a good example and get started."

"Yeah," he replied, doing his best to hide his disappointment. He would have preferred sitting in this cabin and wriggling as many smiles and hair tucks as possible out of Lily but unfortunately she was right. Setting a good example was what he'd willingly signed up for.

He quickly stood and opened the cabin door and waited for Lily to exit first. She smiled shyly (yes!) at him as she walked out and he mentally cheered once again. Everything was going as he'd hoped.

As he entered the corridor he felt a wave of something wash over him and mentally cursed. Six years in the orbit of the walking, talking idiocy that was Sirius Black had taught him that anything odd or unexplained most likely had an unpleasant, embarrassing explanation.

Was Remus the last one to exit the cabin after the meeting? If so he could have cast something on the way out the door. His friends were the absolute worst.

He quickly looked at Lily and breathed a sigh of relief that she still looked normal. No new appendages, vanished clothing or fluorescent skin tones. She was looking at him oddly though. Maybe the prank had targeted him only.

"Is something wrong?" he asked, attempting to act as innocent and unaware as possible. It wasn't even an act for once…he really was most likely the innocent victim of Sirius and his fellow Marauders.

"No," she answered. "I thought I felt something but…" she paused to consider him, "I'm sure it was nothing."

It appeared that Lily had initially suspected that his merry band of idiots had done something to her but she was giving him the benefit of the doubt. She'd finally started thinking the best of him instead of the worst and it was about to be shot to hell.

He nodded at her and smiled, doing his best to act as normal as possible. She hadn't gasped or shrieked so apparently he was pulling it off…so far. Best to proceed as planned and hope for the best.

Within seconds of beginning their trek down the corridor his stomach sank. It was clear that something unexplainable was happening because not only were all the faces they passed unfamiliar, their clothing and hairstyles seemed slightly off. Whatever spell his friends had managed it was seriously impressive in its complexity and nuance. Regardless of that fact his revenge would be swift and merciless.

He kept his thoughts to himself as they continued their patrol. Unless and until Lily expressed a concern it was best to pretend nothing was amiss. Hopefully whatever was going on was only affecting him and would pass soon. He chanced a glance at Lily and was relieved to see she still looked the same…especially her eyes. He really loved her eyes.

James decided to simply look straight ahead and do his best to avoid looking at any more of his distorted classmates. If Lily thought everything looked fine he was sure it was fine.

They'd made it halfway through their patrol before an audible gasp from Lily brought him to a stop. He turned to see that she'd placed a hand over her mouth in shock.

"What? What's going on?" he asked.

She didn't speak, choosing instead to point toward a nearby cabin. He turned to take a look at what had her flummoxed.

There were three students who looked to be starting their third or fourth year while someone else was huddled away in the corner. There was a skinny boy with red hair and a girl with bushy hair that looked just as unfamiliar as all the other cabins that they'd passed. The pair seemed to be in the midst of an argument while the other boy…a boy that looked suspiciously like a younger version of him…did his best to ignore them.

As he continued to examine the boy's features he realized that they looked disturbingly similar, the only differences being a jagged scar on his forehead and his eyes. His eyes looked just like-

He was going to murder Sirius.

As he continued to try and process what was happening Lily opened the door, drawing the attention of its inhabitants. He wasn't sure how it was possible but the three students looked even more bewildered and confused than he was feeling.

"Mum? Dad?" James Jr. muttered disbelievingly,

"If this is some sort of a joke it isn't funny!" the girl declared angrily as she drew her wand.

His first instinct was to reach for his wand but was stopped by Lily's calming hand on his arm.

"I promise you we aren't pranking you. Are we James?" Based on her tone it was clear that she was asking as much for her own edification as for James Jr. and his friends.

"No!" he blurted in a panic before calming himself and trying once again. "No, we aren't."

"Than why are you pretending to be Lily and James Potter?" James Jr.'s friend asked.

"I'm sorry, what?" Lily asked.

"This isn't funny!" the girl scolded as she moved to stand in front of James Jr. All three of the children had their wands out now and the girl's hideously ugly kneazle seemed ready to pounce at any moment.

"Everybody calm down," he managed to spit out as confidently as possible. The jig was up and it was time to come clean.

"I think my friends have cast some sort of enchantment as a joke and we're all seeing things that aren't there. Unfortunately you three have been caught up in it as well. I'm sorry"

"I'm going to throttle Black!" Lily grunted, drawing gasps from the three children.

"She's not serious, obviously," James quickly clarified, ignoring the fact that he'd inadvertently made the same stupid joke he'd been subjected to for years.

"And if Remus and Peter were involved," Lily continued…ignoring his attempt at de-escalating the situation. He started again.

"Let's talk this through and start sorting this out. What year are you starting?"

Now that a bit of calm had been restored the other two seemed to be taking their cues from James Jr.

"Third," he eventually responded.

"Great!" James exclaimed as pleasantly as he could manage despite none of this making sense. "You know our names but we don't know who you are."

Despite being older and Head Boy he couldn't help being a bit intimidated by the young girl as she scrutinized his every word and action.

James Jr. spoke once again. "He's Ron Weasley, she's Hermione Granger and I'm Harry…

He knew the Weasley family and none of them had attended Hogwarts for several years. So now they had a made up Weasley added to the mix. Fantastic.

There was a pause, as if the boy was assessing their reaction before continuing.

"Harry Potter."

"Right," James responded tiredly, "I forgot. We're your mum and dad after all. Who's your friend over there? Grindelwald?"

As he waited for an answer he did his best to ignore the lump frantically darting around in the redheaded boy's jacket. They had enough to sort out at the moment without adding another psychotic pet into the mix. That hideous kneazle was more than enough to deal with.

"We've never met him but according to his case he's a new professor," Harry informed.

He heard a gasp from Lily and felt a keen sense of déjà vu as one hand was over her mouth and the other was pointing at the luggage rack. James squinted to try and read the nameplate on the battered case.

"Professor R.J. Lupin."

He was going to fucking murder Sirius.