A/N: The Cover Image is from upthehillart on tumblr. I do not own Harry Potter or any of the characters.
"So Prongs, is there anything I can help you with or did you come here because you're bored," Remus asked.
Instead of an answer, James gave him a sheepish grin. Remus rolled his eyes in mock reprimand and resumed plotting down his recordings, but couldn't help the fond smile that escaped his lips. James was an Auror and sometimes he required help from the Unspeakables on the case he was working on, but he was also known to wander down the Department of Mysteries just to chat with Remus when he wasn't in the mood for filling out paperwork.
Remus was an Unspeakable - he loved his job and was grateful to have a stable income that enabled him to afford a regular supply of Wolfsbane Potion. He almost got used to thinking of himself as a normal wizard, but he never forgot the kindness and support his best friends showed him back when he thought himself a monster. Their bond had been tested twice; in their sixth year at Hogwarts when Sirius goaded Snape into following Remus on the night of the full moon (had something happened to Snape that night, Remus would have never forgiven Sirius). But nothing was worse than 1981 when Peter betrayed them and Lily and Harry were killed. The years that followed were filled with pain, anger and guilt. All Remus remembered doing was sleeping 12 hours a day, reading about the trials, unsuccessful job applications, counting the days until the next full moon and fearing that James would kill himself - and all the while the world was celebrating. Now, seventeen years later, each of the remaining Marauders had a job and their own place to call a home, but they spent almost as much time with one another as they did back in their school days. Even though Remus drank Wolfsbane and didn't really need them around for transformations anymore, Sirius and James would come every single full moon to keep him company. Everything seemed okay.
"What do you use this for, then?" James asked, referring to a glass dodecahedron. It was an ancient magical artefact, 6 feet tall with one of the faces serving as a door - it reminded Remus of a greenhouse. Inside it, in the very centre was a glowing ball that resembled a small star and the light reflecting off the glass made interesting rainbow patterns. Its surface was carved with hundreds of runes and the purpose of most of them was still being studied.
"Sorry Prongs, you know I can't share department's secrets," Remus said with a smile and once again focused his attention on the work before him. He didn't get a chance to lift his quill before being interrupted by a golden glow that the dodecahedron started emitting. James was standing next to it with a guilty look on his face. "What the fuck did you do," Remus hissed angrily as he jumped from his desk, "you should know better than to play with anything here!" He approached the dodecahedron just in time to see the golden glow fading and leaving in place - a person.
"James, tell me exactly what you did before this happened!"
"I-I am not sure, I just brushed my hand over this area here," he explained.
Remus took a deep breath, "Okay, please tell me you remember which runes you touched."
James pointed out five runes and Remus quickly copied them down on a piece of paper. He then took another look at the person that laid unconscious inside, looking eerily familiar: It was a slender teenager dressed in muggle attire with messy, black hair, strong jawline and round glasses.
"What did I do," James whispered, glancing at Remus.
"I don't know Prongs, but my best guess is that you somehow pulled your younger self forward in time."
James was pacing in front of the fireplace at his apartment. Questions raced through his mind, but no logical answer came to accompany them.
He had followed instructions that Remus gave him and covered the boy (himself?) with the invisibility cloak and quickly ran back to the Auror Department to sign off. When he arrived home, he placed the boy under a strong sleeping spell, checked him for injuries and searched him. He found only a mokeskin pouch and a wand - neither of which had belonged to him at any point in time. He sent patronus messages to Sirius and Albus, asking them to come as soon as possible. He wasn't sure what prompted him to contact Dumbledore, but the relief he felt upon seeing him arrive assured James that it had been the right thing to do.
"Professor," James sighed, "thank you for coming on such short notice."
"It's not a problem, James, it's always good to see you," Albus said with a smile, "tell me what happened."
"I have a visitor that needs identifying," James replied, leading Albus towards the couch where the boy was sleeping.
A whoosh of flames was heard again, signalling Sirius' arrival. "Hello Albus, hi Prongs, is everyone alright?"
"Everyone is fine Padfoot, or at least I will be until Moony murders me," James said and then explained what happened earlier. He finished by stating Remus' first theory, but pointed out that the wand wasn't right.
"He does look a lot like you did when we graduated, but I don't recognize the clothes and the glasses are different shape as well, look," Sirius pointed out.
Dumbledore cast a few spells on the boy and then paused, seeming deep in thought. "I suggest we wait for Remus to come," he finally said.
James made them tea and, remembering how Albus always offers them sweets when they come to his office, he returned the favour and brought out some caramel cobwebs. By the time they finished their tea, Remus arrived with an armful of books.
"Well Prongs, the good news is that we don't have to fear for our timeline changing," he said, "as I am almost certain that one of those runes stood for a parallel universe."
"A parallel universe," James repeated, shocked.
"It's like an alternative dimension," said Remus, "are you all familiar with the theory?"
"I know the theory, but I never believed that it was actually true," Sirius said.
"Well, in the Department of Mysteries parallel universes have been studied for a long time, and while we are certain they exist, we haven't yet had any occurrences of travel between them," replied Remus tiredly, "or if we did, they could be classified and I probably wouldn't be told as it is not exactly my area of research."
"Do we have a way of sending him back," Dumbledore asked.
"I'm positive that I can work it out, I've already picked out all the books that contain the runes that James might have touched; however, we have to talk to the younger James first to find out when does he come from."
"So, you still think that the boy is James," Sirius asked incredulously.
"If he travelled through space, why wouldn't he be able travel through time as well. It cannot be a coincidence that it was Prongs who touched that dodecahedron and then a person who looks like him just appears inside."
"I don't know, Moony," James replied, "his wand is different and I don't remember ever having the clothes that he is wearing."
"That is the whole point of an alternative dimension," Remus explained, "things are different. Who knows, maybe in that universe you were sorted into Hufflepuff."
James had a hard time believing him, but Sirius clapped his back and said "Don't worry Prongs, if there is a universe where you are a Hufflepuff, then I am one as well; there is no way the Hat would have separated us."
The blue eyes behind the half-moon spectacles were twinkling, but Albus had yet to give his opinion on the identity of the dimension traveler. "Well, gentlemen, I think it's time for us to talk to our visitor. However, if there is time travel involved, it would be wise for the three of you not to be in the same room to begin with, as it would cause some confusion."
The three Marauders nodded in agreement and stayed in the kitchen while Albus went back to the living room. They held their breaths as they listened to the shuffling in the adjoining room and the whispered "Rennervate!"