Oct 1 1958 21 47 01

The math and theory behind time travel wasn't nearly as difficult as it might seem. Of course, Doc already had the answers - 1.21 jigawatts, 88 mph, flux capacitor - he just needed to fill in the details. It was like doing math homework to the odd numbered questions. Of course, just because he could write the proof didn't mean he could travel through time. That part would need to wait until he could pick up some plutonium in the future or predict another lightning strike. If only he still had his credentials at Los Alamos, he was sure he would be able to steal the needed radioactive element for his experiment. Of course, the Manhattan Project had been disbanded for over a decade now.

Getting up to 88 mph was not a simple task either, and even if Doc spent his dwindling fortune on a new Ferrari or Corvette, it possibly wouldn't be able to produce the necessary flux dispersal. Using a 1950s car, without a stainless steel body, Doc would either need to increase the velocity or increase the electrical output to make up for the loss of flux dispersal.

The previously pristine and organized detached garage at 1640 Riverside was now a chaotic mess. Mail, papers with formulas and notes scribbled on them, trash, and other debris were scattered throughout the two-car space. A number of letters had the words "Past Due" and "Final Notice" in big red letters on them. Sitting on top of a pile of papers was a letter from NASA addressed to Doc that began, "We regret to inform you." Doc had applied to the NASA program to be one of their scientists, but the psych evaluation he underwent was considered inconclusive and he was deemed too much of a risk. His Top Secret clearance he had while working on the Manhattan Project was no longer valid; in fact, he had it revoked just before they pulled the plug on the entire project.

The only part of the garage that wasn't covered in an unorganized scattering of papers was a single table, where a ripped up sheet of paper lay pieced together face down as if it were a puzzle. Doc had not been able to convince himself to destroy the letter, but he still refused to read it. The impact of knowing his future was still unknown, and self-preservation was enough to keep Doc from burning that bridge completely.

"To understand time travel it is necessary to understand the nature of time," Doc said into his audio recorder. "In order to do this I will need to answer one important question: is our timeline mutable or immutable?" Doc assumed this question was easy; he knew that Marty came to 1955 from the future and changed the futures of his parents, Biff, and potentially all of mankind. On the chalkboard under "Mutable," Doc wrote his bulleted assumptions:

Marty is actually from the future

Marty's parents told him the truth about how they met

Doc had no reason to disbelieve these assumptions, but he felt it was important, scientifically, to remain unbiased. "Of course, there remains the possibility that the timeline is immutable," Doc began to consider out loud. "This would of course mean that Marty misunderstood the circumstances of how his parents met, because the only version of November 12, 1955, would be the version that Marty and I experienced together." Just the mention of Marty's name out loud had more of an impact on Doc than he expected. Doc always prioritized his work over socializing. Despite this, Doc couldn't deny it. He missed his friend.

Snapping himself out of it, Doc called out to his dog. "Here, Copernicus!" Doc sat down, then Copernicus jumped onto his lap. "If time is immutable, an individual's own experience, such as Marty's, may not be linear, but the timeline of events remains unchanged. From the perspective of time, Marty's experiences during his week long visit to 1955 impacted his own future, even before he himself experienced it. Going back in time, even to intentionally change history, will only reinforce its events, since these choices have already been factored into the present." Doc had nearly convinced himself of this theory, but there remained too many seemingly impossible factors: the photographic evidence, the story of how his parents met, plus the uncharacteristic behavior of his father. This would also eliminate any sort of free will, since everything that will happen is already predestined.

"No, the immutable timeline theory could not apply, at least not in the first iteration. With infinite iterations a mutable timeline could become immutable. It wouldn't be immutable by nature, but simply because actors continue to act in an exact manner under identical circumstances in some type of infinite loop." Copernicus jumped off of Doc's lap, and Doc was now pacing back and forth, holding his audio recording device with the microphone to his face. "Of course!" Doc exclaimed. "Multiple iterations! A specific timeline is not mutable, but instead the act of traveling to the past itself creates a unique—a separate and distinct timeline where each coexist simultaneously."

Doc walked over to the chalkboard excitedly, grabbed the chalk, and wrote "two timelines" on the board. "This, being the first iteration of time travel has created an additional timeline," Doc continued. "There is the timeline where Marty's parents meet and fall in love without any interference from Marty. This is of course the prime timeline Marty grew up in. There is also a timeline where Marty comes back, interferes with his parents, and changes history. There may be similarities between the two, such as Marty being born, but make no mistake, it is a separate existence with separate people who may have identical DNA." Doc was getting increasingly more excited about his breakthrough. "So when I sent Marty back to the future—" Doc paused, now with concern on his face. "Great Scott!"

Oct 27 1985 23 23 00

Marty stood in Doc's garage, waiting. The German woman told him her name, but nothing else. "Is that supposed to mean something to me?" Marty finally yelled, breaking the silence.

"I thought you were friends with Doc." Sofia responded, a little confused.

"Why does everyone keep saying that? Mr. Brown was my teacher."

"What? So you know nothing about Doc's past?" Marty shook his head. "Do you know anything about his experiments?"

"A little."

"How can you be his research assistant and partner?"

"Can you just tell me what the hell is going on? Do you work with the FBI? No, not with that foreign accent. Interpol? Am I in trouble in Australia now, too?"

"You think my accent sounds Australian? Have you ever met an anyone from Australia?"

Before Marty could respond they hear sirens in the distance. "You have the DeLorean?" Sofia asked.

Marty was caught off guard. Sofia seemed just as worried about the approaching police as he was. "Um...yeah."

"Quick, let's go!" Marty decided that going with Sofia in the DeLorean was a better option than sticking around and waiting to get arrested. Sofia grabbed the keys from Marty and they both ran to the DeLorean. They quickly sped off, unseen by the police.

Marty had been in a state of confusion all day. He was trying to figure out what questions to ask Sofia when she finally broke the silence. "Erhardt von Braun."
"What?"

"He's my great uncle."

"Who?"

"Doctor Emmett Brown's father."

"Oh shit, you're related to Mr. Brown? So he's your cousin? No, that's not right."

"His father is my grandfather's brother."

Marty still trying to figure it out, "I'm going to have to look at a family tree or something."

"I am giving you answers, so I am going to need some answers from you."

"Before we do that, I have a few questions of my own. Starting with, where the hell are we going?"

"I have a motel room just outside of town, we can lay low there while we figure things out. Can I ask you some questions?"

"Sure."

"How long have you been in the wrong timeline?" While Marty was too shocked and exhausted to begin to try to answer the question, he did feel relief that someone recognized his situation for what it was.

"Wrong timeline" Marty muttered to himself. He finally had a term for what was happening, even though he still didn't know what it meant. Marty opened his mouth to speak, but before he could make a noise, Sofia pulled into the motel.

"Why don't you get settled in, I have a change of clothes for you." Marty went into the room and instantly fell onto the bed. With all the excitement he hadn't realized just how tired he was. He fell asleep almost instantly, fully clothed once again. While he still had still had many outstanding questions, he was comforted by the idea that someone may be able to understand, and perhaps correct, the current nightmare.

Marty began to stir himself awake. He had a terrible headache and couldn't make sense of his unfamiliar surroundings. "Gotta get up and go to school," thought Marty. He slowly opened his eyelids and sat up quickly. The details of the previous night were slowly coming back to him.

"Unfortunately for you, it wasn't a dream," Sofia called out from across the room, which Marty finally realized was a grungy motel room. She was sitting at a desk looking through papers.

Marty sat up, now fully awake. "God. Is this place hell?"

"It's not hell, it's the effects of time travel," Sofia said.

"I can't imagine hell being much worse. Wait, time travel? I haven't travelled through time-"

"Well, in your case, you travelled sideways to an alternate universe."

"Alternate universe? Well, that explains—"

"The original Marty must've—"

"Whoa, wait. Original Marty!?" interrupted Marty. "Are you telling me that I'm some kind of—clone!?"

"Take a look at this," Sofia said, choosing to ignore Marty's last question. She laid out Doc's notes, including a drawing of the time circuits. "These are Doc's plans I took from his lab."

Marty slowing walked over, rubbing his eyes. "The time circuits!" Marty said excitedly. "Mr. Brown showed this to me. Month, day, year, and time. I don't get what this has to do with—"

"And this," Sofia interrupted as she pulled out a sketch, "is what the time circuits look like on the DeLorean outside. Notice anything different?"

Marty looked back and forth between the two, unable to see the difference. "This extra column," Sofia finally pointed out, showing him the extra unlabeled boxes in her sketch. "You may not have noticed, but your DeLorean has an extra number to the right of the time."

"Is it for seconds?"

"I don't think so. I noticed this last night. But this means that the person who wrote these plans is not the same person who built that time machine," Sofia said, pointing outside to the DeLorean. "These plans were used to build the original time machine."

"Original, original. Why do you keep saying that? Are we not real?"

"Not we, just you. But no, you are very much real. You see, different dimensions are created iteratively."

"English, Sofia!"

"I don't understand, I am speaking English."

"No, I mean...just explain it again using simpler words."

"Ok." Sofia grabbed a blank piece of paper and drew a line on it. "Imagine this is the original timeline, we'll call it timeline 1. In this timeline Doc invents a time machine, and at some point it is used to go back in time."

"Except he didn't go back in time, he died before he could use his invention."

"As far as you know, but you aren't from the original timeline. You are from this timeline." Sofia draws a slanted line coming down from the original timeline, then another line parallel to the original and labels it "Timeline 2."

"Whoa, this is heavy."

"You see, the time machine was used to go back in time, and in that process something changed and that created a new timeline."

"Why do you assume that you're the original? Isn't it just as likely that I'm the original, and everyone here are copies."

"Not copies, just from universe 2."

"Whatever, universe 2! Clearly someone really messed up somewhere and created this hell hole that we are in now." Marty didn't want to believe what he was hearing, but it was really the only thing he had heard that could explain any of this. "So, let's assume that you are right, and I am from a different universe. Then where is the Marty from this universe?"

Sofia looked up at Marty with the pencil resting in her mouth. "That is the question now, isn't it?" She pointed at Marty with her pencil as she continued. "He seems to have disappeared at the same time that you appeared, so my initial theory is that you have switched places."

"Switched places? Like Freaky Friday?"

"Freaky what?"

"Friday, the movie. With Jodie Foster." Seeing that he was getting nowhere, Marty changed thoughts. "Does this mean that my life has been stolen by...me?"

"Precisely. And I believe the DeLorean that we have is not only a time machine, but a vehicle to travel to alternate dimensions. The additional column, while unlabeled, is unmistakably a universe indicator."

Marty continued to ask questions as Sofia attempted to get clarification on details of how and when Marty traveled from his universe to the this one. As the discussion continued it became clear that they needed to use the machine to travel to universe 2. They set out to figure the best time to try to find the original Marty to get more answers and get each to the proper home.

"I can't imagine he wants to come back here either, though. Did he do this to me on purpose?" Marty began to wonder what he would be capable of if he grew up in this reality. Would he intentionally ruin someone else's life?

"There is no evidence of that. For all we know this was accidental, and the Marty from this universe is just as lost as your are."

Sofia and Marty exited the motel room and got into the DeLorean. Sofia began to drive away from Hill Valley as Marty was taking a closer look at the time circuits, noticing the extra column. It was still daylight, and the FBI were likely still looking for them, but they were now so far into the desert that they hadn't see another person for miles. Sofia stopped near a long stretch of paved road. "There is no time to waste."

"We got all the time we want, we're sitting in a time machine," Marty responded. Despite the irony though, Marty knew Sofia was right. The longer they spent in this universe, the more likely it was that the authorities would find them and continue to ask questions that didn't have believable answers.

"This should be enough road to get up to 88 miles per hour," Sofia said as she started touching the dials of the time circuits. "We know we have to go to universe 2." She flipped a switch to make the last column display the number 2. "But when was it that you first entered this universe?"

"It had to have happened when I was at Lone Pine Mall, where Doc got killed, early Saturday morning."

"Let's set it for 2:00 AM October 26th," Sofia said as she entered the coordinates. "We are a couple hours outside of Hill Valley, and then we can lay low until morning." Marty and Sofia got out of the car and put on hazmat suits to refill the DeLorean with plutonium.

Just as they completed the transfer of radioactive material, an old man in a beat-up pickup truck pulled alongside them, yelling and taking pictures with his camera. "Who do you work for, the FDA? FBI? Are you poisoning our water? Trying to brainwash us with fluoride!?"

Marty took off his hazmat helmet. "Get the hell out of here! It's none of your business."

"Keep your helmet on!" Sofia said to Marty in a hushed voice.

"It's my business if the government is using alien technology to spy on its citizens! What kind of futuristic device is this, anyway?"

"We gotta go," Sofia said. She pushed Marty into the DeLorean and managed to get in the driver's seat herself while the man continued to yell.

"I'll be sending these to the Weekly World News," the old man yelled as he ran back to his truck to follow the DeLorean. The pickup truck was no match for the speed of the DeLorean. The old man looked out into the distance as he saw the futuristic car shrinking, but not quite disappearing in the long straight desert road, until he saw what unmistakably looked like two lines of fire. As he got closer to the fire trail left by the tires, he stared in shock. He took picture after picture of the fire until he finished his roll of film. He slowly wound the film, the subtle clicking sounds from each stroke of his thumb breaking the otherwise silent desert road. He then took the film out of the camera, put it into an envelope to be developed, grabbed a pen and wrote a note on the envelope: "spontaneous combustion."