Lan Sizhui winced as Lan Jingyi opened the door, hearing the hinges squeak deafeningly in the otherwise-silent night. Head disciple or not, causing a ruckus so close to curfew was just asking for Lan Qiren to find them.
Jin Ling seemed to have similar thoughts, and (with a fear that had never been completely erased even after becoming sect leader) quickly pushed Ouyang Zizhen inside while Sizhui ushered Jingyi in. Luckily, it seemed everyone was too far to notice them.
Or, in the case of Wei Wuxian, too distracted.
"Xian-gege?" Lan Sizhui asked, peeking around the wall his senior disciple was hiding behind only to find enormous stacks of scrolls, notes, and books blocking his sight.
"A-Yuan? Is that you?" a voice asked from behind the mountain. "Come in, come in! I've got something to show you!"
Exchanging a skeptical glance with Jin Ling, Lan Sizhui navigated his way through the man-made canyon and finally found his target buried knee deep in papers.
"Wei Wuxian!" Jin Ling bustled forward, paying no mind to the precariously placed books he was knocking over. "Hanguang-jun ordered us to make sure you didn't stay up all night working while he's gone! This can wait until tomorrow!"
"In a minute~" Wei Wuxian complained, not even pausing in his rushed flurry of notes. "If I stop now I won't remember my train of thought in the morning!"
"But Xian-gege-"
"What are you working on anyways?" Lan Jingyi asked, peering over and trying to make sense of the rushed scribbles Wei Wuxian was pouring out.
"Are you interested? Maybe you can help me out." Wei Wuxian suggested, turning to them with a mischievous look (which was much less scary when combined with the gargantuan dark circles under his eyes).
"If you've stayed up several nights in a row for this I doubt we'd be much help," Jin Ling scoffed, but settled down regardless.
Soon all four boys were seated in a semi circle around their teacher, tired but captivated by the promise of an interesting lesson. Not only was Wei Wuxian the best teacher they'd ever had, more often than not he was teaching them something no one had ever seen before.
Though, considering Wei Wuxian created nearly every advancement the cultivation world had in the last two decades, maybe that wasn't surprising.
Wei Wuxian observed his captivated audience, then swung his arms open for a dramatic reveal.
"I'm mastering time travel!"
The juniors stared, blinked, and sat in befuddled silence.
"...What?" Jingyi finally asked.
"Time travel! Traveling through time! I found some notes in Jin Guangyao's library on a book I'd made on the subject, and I think I'm really on to something!"
The juniors slowly nodded in understanding, contradicting the blank looks in their eyes. Surely, they must have misheard?
"Like… through time?" Ouyang Zizhen checked. "As in, you could walk around in the past and see your past self?"
"Ah… not exactly. See, transporting matter through time would take a whole lot more energy than we're actually capable of. If every cultivator in the world sacrificed all their spiritual energy to send things back, we… might be able to transfer a flower petal."
"Then what's the point!" Jin Ling demanded.
"The point, my young disciple, is that we wouldn't have to send back someone. We could send… something."
"...You just said we could barely send a petal."
"No, no, no. Think of it like this, if we send back matter, it wouldn't really change that much. We'd just be duplicating something and probably wouldn't cause any significant changes. If we send back memories, however…"
Trailing off and allowing his students to fill in the blanks, Wei Wuxian turned back to his writing and added a few more points.
"Wait, but then what will happen to us?" Jingyi asked, looking left and right as if the embodiment of time would jump out and attack him.
"No need to worry, I already tested it. I sent back a message to Lan Zhan, but when I talked to my Lan Zhan he had no memory of it. I did a bit more testing, and realized that there was still a Lan Zhan who remembered the message I gave them and…" he trailed off, noticing the lost expressions on his student's faces. They blinked at him a few times, still not understanding what he had discovered.
"...And that means…?"
"Basically, this method of time travel works off something called multiverse theory. Any memories I send back create a new timeline that serves as a parallel world, and thus there's no risk of a paradox wiping us all out of existence regardless of how we use it. It's all perfectly safe!"
"Wait, you were messing with something that could have wiped us out of existence?!" Jin Ling interrupted.
"I just told you that isn't a concern."
"But you didn't know that when you started, did you?"
"Well…"
Instantly he was met with four identical, disapproving looks.
"I promise I was very careful!"
"I'm not sure you know the meaning of that word, Xian-gege," Lan Sizhui informed him without once losing his smile. Wei Wuxian pouted. It wasn't fair; his little radish was becoming more and more terrifying every day! He missed the little three year old he could burry in holes!
Interrupting his silent mourning, Ouyang Zizhen asked, "Wait, if you already know all that, then what are you still working on?"
"Something I'll need your help to test! So far I've seen it work mostly like empathy, involving first-person views and a one-on-one experience. It's just wasteful to use energy to create a new pack of memories for every person, so I'm trying to make it so that people can simultaneously watch the same thing and even interact with each other while they watch. I think, so long as I have more than one memory of the event, they'll combine to create a 3D simulation of whatever the memory is. Will you guys help me test a few things?"
Shining with excitement and interest, all four teenagers nodded enthusiastically.
"Of course!" they shouted.
"Tomorrow," Sizhui added, reminding them all of why they had come in the first place.
Laughing at the sudden looks of disappointment on the other three, Wei Wuxian nodded easily and began packing up, sending the teenagers on ahead.
Minds still consumed by the possibilities Wei WuXian had revealed, the group dragged their feet on their way back, trying to prolong their journey and indignant at being sent away when they were just starting to get excited. Jin Ling and Ouyang Zizhen knew breaking sect rules would get him blacklisted from further diplomatic invitations (not playdates, regardless of what Wei Ying said), but were too preoccupied to care.
"Can you believe it? Time travel?" Ouyang Zizhen whispered, looking over his shoulder in case Lan Qiren was patrolling nearby.
"I can," Jingyi declared proudly. "If anyone can figure it out, it's senior Wei."
Jin Ling nodded distractedly, then muttered "Imagine what we could change with that."
"What do you mean? Xian-gege told us it wouldn't change anything for us. We wouldn't be able to cheat on tests or anything."
"Right, but… maybe then there'd be at least one universe where my parents are alive."
All four suddenly stopped mid-step, and Jin Ling blushed when he realized what he had just said. He was practically an adult (and a Sect leader on top of that)! He shouldn't still be caught up in daydreams of his parents.
"I mean, I just think Wei Wuxian isn't valuing what he could do enough."
"No, you're right," Lan Sizhui murmured, a contemplative expression on his face. "If we could do this, maybe we'd be able to make a world where people actually listened instead of just assuming things about Xian-gege. He wouldn't have to die, and Hanguang-jun wouldn't have had to spend years in seclusion."
"Nie Mingjue wouldn't have been killed-"
"And Lan Xichen wouldn't be in seclusion now after the betrayal of his sworn brother!"
Jin Ling nodded, his enthusiasm rising again.
"And Uncle's parents might not have been killed during the Sunshot campaign!"
The teenagers turned to each other, no longer bothering to keep their voices down despite the late hour.
"Sect Leader Jiang and Senior Wei wouldn't misunderstand each other!"
"Senior Wei wouldn't have lost his core!"
"Hanguang-jun and Senior Wei could have gotten together sooner!"
"Wen Ning wouldn't have to die either!"
"We could change everything!" they shouted simultaneously.
One week later — which, according to Wei Wuxian, would have only taken two days if he'd been allowed to make a couple all-nighters! — and the prototype was done. Wei Wuxian had designed it into a red, crystalline orb which would accept memories from whoever touched it and read the user's intentions to figure out the time period it was sending them back to. The quartet of teenage troublemakers (or 3 troublemakers plus Sizhui) had their opportunity quickly approaching with Hanguang-jun's impending return (signaling a night where Wei Wuxian would be otherwise occupied).
Their operation would commence at dusk.
"Shouldn't we figure out what memories to send back first?" Sizhui asked them on the night before the Second Jade's return. "I mean, I'd rather just use the night he's back to send everything along. It'll be difficult if we need to figure that out first."
"Well, we should definitely include my memories of Jin Guangyao's death since everything was revealed right before then."
"I guess we could include a history class of learning about the sunshot campaign?" Zizhen suggested uncertainly.
"Right, exactly. The main problem is that we weren't there for most of it! Should we ask Hanguang-jun and senior Wei for their memories?"
Sizhui frowned, then shook his head.
"I don't think I'd like to force them to remember those things. It'd be more accurate, but… I don't think I can do that to them."
The others nodded in reluctant agreement, scowling in frustration. Lan Jingyi sat down on the grass, beckoning one of the nearby rabbits over to himself. A soft, light brown one crept over and nuzzled into his lap, relaxing as Jingyi ran a finger through its fur.
"Wait, that's it!" he shouted, startling the bunny into jumping off him.
It ran directly over to Sizhui, who asked, "What's it?"
"They weren't the only ones there!"
Jin Ling looked over sceptically. "I don't think the bunnies can transmit memories."
"And Sect Leader Jiang will probably kill us if we ask him."
"No, no. Remember what Senior Wei said? It's like empathy. If we combine the memories of a bunch of different ghosts, we'll be able to get a view of everything that happened between them. Besides, Senior Wei is basically their master, so maybe they'll even be willing to put the memories together for us!"
As he continued to speak, his friend's faces quickly brightened in realization. Jingyi was right! If they did that, they wouldn't even need Wei Ying's memories. All they had to do was ask the spirits for help.
Immediately, Lan Sizhui rushed out of the cloud recesses and pulled out his guqin, playing inquiry with as wide a range as he could. Although no spirits could exist inside the Lan clan's protective barrier, there was a strong chance the spirits could either see from the outside, or had been present when they were still alive. As sobering as that was, perhaps an alternate version of themselves would survive with the information offered.
And, most interestingly, Wei Wuxian used music to order the spirits around. The commands were transmitted through sound, yes, but the intention transferred telepathically. They might have even greater insight into Wei Wuxian's mind than his the kids had.
A second later, a spirit responded.
"They think they can do it!" Sizhui reported, brimming with happiness. This way, they'd be able to get a truly complete version of the story to all the people who need it.
"Who should we send it to?" Ouyang Zizhen asked nervously.
"My parents and grandparents, obviously," Jin Ling declared, though he wasn't as sure about his paternal grandparents given the rumors about Jin Guangshan.
"The Jiangs too, for both your uncles." Sizhui added. "And the Lans."
"Nie Huaisang and Mingjue will need to know too," Lan Jingyi added. "Maybe we should just send it to the main-line of the great clans back then. Senior Wei said it was based off intentions, right? We'll just 'intend' to send it to the most important figures in the most famous clans."
The quartet nodded in excitement, continuing to conspire with each other towards their shared goal of creating a world without the stupid, stupid misunderstandings people kept having about Wei Wuxian.
However, in their haste, they overlooked two important facts: First, Wei Wuxian was never officially adopted by the Jiangs, and therefore would not be included. Second, in the time period they were aiming for, there were five great families.