Disclaimer: I don't own Back to the Future. I do own the IDIATM AU, though.

Author's Note: All right, to anyone who hasn't read my long epiloguish author's note that I posted on Travelling Through Dimensions, this story is a sequel to "I Didn't Invent Any Time Machine", and tries to tie up some loose ends or plotholes that I left there when I first wrote it. Why, for instance, do the main characters of the story not erase once they get back to the "good" world, since they already have counterparts there? Is Marty Two (Calvin) special, or similar to everyone else from the A-timeline, despite not originally being from that timeline? Chris has Susan, but is Doc ever going to meet Clara?

All these questions will be answered in this story, a story that starts only two weeks after the previous one left off but might feel differently due to the fact that I wrote it so much later. I came up with the core concepts of the story all the way back in 2012, though (even if I hadn't quite worked out all my ideas yet by that time). I hope you like it. The first chapter is more of an introductory chapter, in part designed to remind you of the nature of this world, but the cliffhanger at the end pushes us directly into the main story. If you have any questions or comments or you either like/dislike the story for a reason, by all means, please review!

Existing Outside An Erased World

Chapter One

Saturday, December 14, 1985
8:30 AM PST
Hill Valley, California

"Tell me doctor; Where are we going this time; Is this the fifties; Or ninety-ninety-nine."

Calvin Arthur McFly began to come to with a smile on his face, listening to the familiar Huey Lewis music that was warbling from the speakers of the radio in his room. It was one of the songs Huey had recorded for Calvin's favorite movie, 'Teens in Time', and indeed the song was very appropriate to his situation. It never ceased to make him smile.

As he listened to the lyrics, Calvin rolled over, realizing that once again he had slept with his clothes on. He knew that his mother would still complain about that every now and then, but the frequency of their rows about it had decreased a lot since the previous timeline, as had their seriousness. Lorraine Baines McFly was very well aware that she couldn't get her son to change his habits on this subject, not unless she was prepared to personally take off his clothes every single night. And it wasn't like his twin brother wasn't the same.

Even after two weeks, the thought of him having a twin still confused and unnerved him, especially since that twin was named Martin Seamus McFly. After all, that had been his name, all his life, or at least until that October day Doc Brown had invited him to his demonstration of the newly invented DeLorean time machine at Twin Pines Mall. Half an hour later, his best friend since childhood had been dead at the hands of some Libyan terrorists, and he had been sent back to 1955, where, worst of all, he had to spend an entire week getting his not exactly matching parents back together. And all of it under the eyes of an Emmett Brown whom Calvin – then Marty – had desperately attempted to inform of his impending fate. And when he finally succeeded at his job and left 1955, he had arrived in the hell Biff had made of the world after receiving a certain sports almanac as a teen. It had taken him and the locals two months to get out of there, and when he got back to the 'real' world – a world which now featured his father as a successful author and his mother as a happy, non-alcoholic housewife – there had already been a version of him there. And because of that, he had been forced to abandon his own identity and adopt a new one – that of his counterpart's fictional long-lost twin, Calvin Arthur McFly.

Since then, he had had to adjust to an essentially new version of his parents, and to what perhaps even harder; the idea that he wasn't himself anymore. His counterpart was the one dating Jennifer, his counterpart got the credits he'd worked hard for on school prior to October 26th… Of course, since the local Marty was him, the other teen had done the exact same work as well, but that didn't exactly ease Calvin's worries.

Trying to shake off the depressing thoughts about his past, which always seemed to come at a time like this, Calvin rolled over and looked at the clock. To his honest surprise, the time it gave was 8:32 – not exactly the time of day he was used to getting up on Saturdays. Mumbling in frustration and confusion about the odd time, Calvin reached over and turned the alarm clock off, simultaneously cutting off the still-continuing Huey Lewis music being played on the radio. Sighing, he let go of the alarm clock and leaned back in his previous position, content to dream for another while yet.

He might indeed have fallen back asleep, if not for his mother appearing in the doorway shortly thereafter, smiling at him. "I was wondering whether you'd turned off the alarm clock" she said. "Honey, are you all right?"

"I'm fine" Calvin replied, confused. "It's just that my alarm was set way too early. I'm pretty sure I meant to get off at 10:30."

"Ordinarily you would, but this is no ordinary day, remember?" Lorraine gently responded. "Today Doctor Christopher Lloyd Brown and his wife are returning from their honeymoon. They're due to be back at 10 AM, and you did want to be there."

Now that his mother said so, Calvin could vaguely recall him intending to do so. Looking back, it was so obvious. Today was December 14th, two weeks after Doc One/Dr. Lloyd Brown/Christopher and his new wife Susan Clayton had left off on their honeymoon to Australia and France, and it had been a two-week trip, even counting the surprise journey to France. Just last night, Chris had called from Paris, informing them that everything was going according to plan and that they would return the next morning at 10.

The thought of Doc – a version of him, at least – returning from his honeymoon reminded Calvin of everything that had changed. The Dr. Emmett Brown he knew, and partly still knew as the final timeline's Doc was mostly the same as his counterpart in the world Calvin originated from, was a scientist who was married to his job. Although Calvin knew he'd had many hobbies in his earlier years (including a one-time dream of being a cowboy) and he had become a fluent player on the saxophone, in his more recent past Doc had become a scientist 24/7, one who had been a good friend, certainly, but didn't really appear to need one himself. Of course, Doc appreciated his friendship with Marty, especially in the new timeline when he had met the teen thirteen years before his birth, but beyond that, Doc was alone and seemed to be content with it. To Calvin, this had been a natural state of being for the inventor until the Doc that would become Chris had met up with Susan Clayton, back in the Biff-ruled world. The two had hit it off right away, and Calvin had bolted from one surprise into the other as it turned out his lifelong friend could not only fall in love, but kissed and danced with a woman, who, if her behavior towards Chris was any indication, seemed to like it and him a lot.

Clearing his mind, Calvin turned to his mother. "That's right" he confirmed. "Is Marty up yet?" His twin brother did share the same problem he had in getting up early, a trait that Calvin carried from the original timeline but which had apparently remained unchanged in the new timeline. If anything, Marty, having led (for one set of memories at least) a much easier life than his twin, had a tendency to be slightly lazier and more inclined to sleep in than his counterpart was.

It was to his surprise, then, that Lorraine nodded. "He is – but I did have to keep a close eye on him as he went down the stairs" she added with a grin. "From the impression he gave me, if I hadn't been there, he would've bolted right back into his bed."

Calvin grinned. "Wouldn't have surprised me" he said, putting his legs over the edge of his bed and yawning. "Is breakfast ready yet?"

"Should be in a few minutes" Lorraine replied. "In the meantime, you can get a wash in the bathroom and rub the sleepiness out of your face. You look exhausted. Were you up late last night?"

"Kind of, yeah" Calvin admitted, although personally he felt like that wasn't the entire problem. For a while now, he hadn't been feeling too well, with stomach aches and insomnia plaguing him. He had had a decent night's rest this time around, but it was the exception that confirmed the rule, and the teen figured that if it went on like this, maybe he should check with a doctor. He was getting the nagging idea that this wasn't normal.

Lorraine nodded and went off at that, mercifully leaving her son alone as he fetched his clothes and went to the bathroom. Fortunately, Dave and Linda seemed to be already awake or still in bed, so he could just go right in. One of the many disadvantages of being younger had always been being last in row in occasions like this, just because his brother and sister were older and stronger than him. His height hadn't helped matters. Of course, now that they were all grown-up or nearly so those incidents didn't occur nearly as often, but Calvin had the feeling that they occurred to him more than to his twin, as if Dave and Linda were making up for the fact that they hadn't been able to tease their new brother when he was young. After all, as far as they knew, Calvin had left the family as a baby and been raised as an only child.

The cover story seemed to stick, thus far. Certainly, he'd had some difficulties at school and on social occasions, ironically more because he picked stuff up too easily rather than not soon enough. After all, most of Marty's friends had been his friends once, and it was difficult to act as if he didn't know them. The first day at school, he had nearly gone off to his new classroom on his own a few times before Marty had clasped him on the shoulder and he had remembered to allow his 'twin' to guide him to his place.

Of course, he did have his worse moments, and most of them involved Jennifer. There was only one of her, and though he did like Ann and Claudia, they were just different, and of course they hadn't known him before. Being without a girl after three years of dating stung – what was worse was seeing Marty still happily dating her. In fact, Calvin had the feeling Marty and Jennifer were closer than he had ever been to her, partly because they now knew that they would end up together in the future, and were subconsciously already anticipating on that. As for him, he hadn't had a single date in the past two months. In fact, the last girl who had given him a real lovers' kiss had been his mother, back in 1955, and Calvin preferred not to count that incident.

Fortunately, he could be distracted easily as he headed down the stairs himself and saw his brother in the living room. Marty McFly looked up as he saw his twin, and the two stared at each other with the incredulousness normal to twin brothers who had grown up without knowing the other existed. Of course, this wasn't exactly the same case, as prior to that fateful October date – or even the twelfth of November 1955 that had followed it – they had been the same person, and even counting the events that differed in the new timeline, the changes in their personalities were minimal – especially when comparing it to the way they differed from the boy who was now Michael Brown, Dr. Christopher Lloyd Brown's adopted son.

"Hey" Marty said, softly.

"Hey" Calvin replied, sitting down opposite him.

"So," Marty began, "do you think Chris and Susan had a good time together?" He chuckled awkwardly. "I still can't believe Doc – a version of Doc – ended up getting married. It contrasts so much with how I got to know him growing up."

"I was just thinking the same thing" Calvin agreed. "Of course, Doc is nice and all, but I do think that a year ago, I would have laughed in your face if I'd heard that he had found a nice and good-looking woman who wanted to marry him."

"Yeah, same here" Marty nodded. Calvin mentally wondered whether they were ever going to have a sibling fight, given how much they agreed with each other. "Of course, Doc – my Doc – did faint when you told him the news, so he took it seriously right away. Then again, given that it came from you and the way you delivered it to him and later to me, we didn't have much reason to doubt you. I certainly didn't – with the whole alternate realities and double me's already baffling me, this wasn't at all that weird to hear."

Calvin nodded. "I did give you quite a shock, didn't I?" he said. "I'm sorry, but I couldn't find any other way to break the news besides just getting you on the phone. And it all worked out for the best in the end, so…" He shrugged. "It couldn't have been that bad for you."

"It wasn't" his brother reassured him. "I was shocked for a few minutes, yeah, but Jennifer helped me get back to the real world. It's not like I haven't experienced stuff like that before. The whole experience of getting sent back to 1955, with Doc dying and then suddenly being thirty years in the past in a time machine without fuel… we really could have freaked out then."

"But we didn't" Calvin mused. "It's a good thing Doc didn't befriend a teenager with a weak heart, then. I know I felt close to keeling over from shock several times. Of course, we did end up getting hit by Grandpa's car, and spending nine hours unconscious afterwards." He frowned. "It's so weird to think that you lived through so many things I lived through as well."

"Yeah, we really aren't all that different" Marty agreed. "Some days, when I'm particularly tired, I'll walk out of my room and see you, and think I'm already in the bathroom and staring at the mirror."

Calvin snorted. "That's weird – although I suppose it's only natural, if you are particularly tired. I can't really blame you anyway, as I'm doing much of the same things. After two months, you'd think I'd have stopped reacting to someone saying Marty."

"Well, it was our name for all of our life, and I know I'd go nuts if I had to get used to another one" Marty replied. "Marty One, er, Michael doesn't seem to have any problems with it, but of course, he's probably eager to leave the world he came from behind him."

"That's true" Calvin said. "And his entire family is adopting new names, so at least he doesn't feel quite like an outcast, the way I do." He frowned for a moment, but smiled again the moment thereafter. "Christopher Lloyd Brown. You'd think people would notice the obvious. Jennifer's Claudia Wells isn't all that famous, so that could pass, but Chris… and especially with him having a son named Michael…well, Mike really, but…"

"Few people notice what's right under their nose" Marty stated. "Chris and his family aren't really trying to draw attention to themselves – and the few people who notice their resemblance to Doc and to us might not know either Michael J. Fox or Christopher Lloyd."

"I could see them not knowing Christopher Lloyd, but Michael J. Fox?" Calvin raised an eyebrow. "Between Family Ties and Teens In Time, you'd be hard-pressed to find someone who hasn't heard of him. Especially in Hill Valley, considering the fact that we resemble each other so much. Of course, Mike is just Michael Emmett Brown rather than Michael Andrew – so I suppose that's just enough to avoid causing suspicion."

"Or so one hopes" Lorraine agreed, as she entered the room carrying plates filled with sandwiches. They had been baked in the family oven, and Calvin thought they smelled very good – especially considering what went for breakfast in the timeline he came from. "Breakfast's ready, boys. Hope you like it."

"It certainly looks great, Mom" Marty complimented her. Calvin nodded.

"Thank you" Lorraine replied. "Your Dad is off to the tennis court, and Dave and Linda were sound asleep the last time I checked, so we have the house for ourselves – or at least, until you leave for Dr. Lloyd Brown's place." She sighed. "I have to admit that time travel is still making me uncomfortable. The thought of being a different person prior to your journey back in time… one of you could go back now and change my life again, and I would never know."

"Well, that's the case for us too" Calvin argued. "After all, we don't own the time machines – the Docs do. And they've got them under guard." He sighed. "I still wonder what possessed him to take those names, though. People will get suspicious. At least they live on opposite outskirts of town, and with future aid, they've got tight security."

"That's right" Lorraine agreed. "I'm still worried that somebody might notice one day, though, and suspect time travel was involved. I admit that it wouldn't be the obvious solution, nor something someone would take seriously right away, but seeing that Mike and his family came from a world which was the result of one person taking one quick journey through time… well, it doesn't bode well for what would happen if someone would steal the car again."

Marty nodded. "They do have tight security, you know" he pointed out. "Future technology is amazing. Last time we went over, before their wedding, Chris didn't open the doors until we had spent almost half an hour giving them passwords and codes and information only we could know. The house may look like an ordinary mansion to avoid suspicion, but underneath it all, it's in the process of getting better locked than Fort Knox."

Lorraine sighed warily. "Well, I suppose you know them better than I do" she said. "I just hope it all turns out well. With time travel, ordinary worries seem to fade into nothingness compared to the paradoxes and erasures that might cause."

Calvin smiled, optimistic. "I don't think we have to worry about any of that right now, Mom" he said. "Doc and Chris have two time machines, so even if one is stolen, we could chase whoever did it and catch him before he can change anything."

Lorraine sighed again at that, indicating that she wasn't reassured yet. Calvin could understand that – he wasn't entirely reassured himself either – and instead just resumed eating his meal.

They finished breakfast after just ten minutes, and after getting dressed and fetching a few dollars as a lame wedding gift to the newlyweds, Marty and Calvin headed off to the former's truck. Although the car wasn't his, Calvin was still incredibly thrilled every time he saw it. He had dreamed of this Toyota truck even before he had travelled through time, and the fact that he was allowed generous use of it by his 'twin' made him forget some of the other problems he had with the new reality. This time, though, Marty was the one to take the wheel, and Calvin didn't blame him – after all, his twin was the one who had more experience driving the car, having gotten his new memories where Calvin hadn't.

Shortly after 9:40, they got to the home of Dr. Christopher Lloyd Brown. Marty hadn't been kidding earlier – the building was locked tight. Fortunately, neither Chris or Susan was home right now, and Michael and Claudia were a little softer on security than their parents were. After a brief conversation at the gate, which Calvin was sure Mike was doing partly to tease them, they were allowed into the house.

"Good morning, Marty, Calvin" Claudia greeted, cheerfully. "Nice to see you can be on time for once."

Marty rolled his eyes at the jest. "We're not always late, you know" he defended himself. "Half the time I got late for school, it was because of one of Doc's projects keeping me up late at night."

"Did somebody call my name?" Doc asked, entering the hallway. "Shame on you, Marty, for lying to our hosts like that. The only time I ever created the specific circumstances that would compel you to be late for school was on the day before I demonstrated my time machine to you, and I had my reasons then."

"Yeah, I guess so" Marty allowed. "You never explained what that experiment was for, though."

"It was a minor thing" Doc replied. "Nothing to do with the actual time machine itself, if that's what you're thinking – that night truly was Temporal Experiment Number One, or at least, it was before you went back in time and I had to perform one thirty years earlier." He shook his head. "It's awfully hard to maintain statistics like that when you're a time traveler."

"Yeah, time travelling does play tricks with your brains" Mike agreed. "Did you receive any new information on when Dad and Mom are due to be here, Doc?"

"Not since the last time you asked" Doc said. He sighed, wistfully. "I wish I could have a honeymoon. After so many years, I'd given up on finding love, but seeing that a counterpart of mine who isn't all too different from me could do it…" The inventor shrugged. "Well, we'll see if that happens some day. The future is whatever you make of it, after all."

"That's true" Claudia replied. "If we'd given up hope during the time we were stranded in that horrible world Biff created, when we were still without a time machine and constantly threatened by Tannen's goons… well, I'm sure we wouldn't have been as happy as we are now then." She put an arm around Mike's shoulder, who blushed awkwardly.

"That's no way to behave around your brother" Marty teased. "Is there something deeper going on here?"

Claudia and Mike now both blushed. "Just because you're dating my counterpart doesn't automatically mean that I want to date your other self" the girl pointed out. "Mike and I are siblings and friends, and we're perfectly happy with that."

"Right" Mike said. Somewhat teasingly, he added: "After all, if we married each other, the potential grandchildren Mom and Dad could have would be halved."

Calvin shook his head, smiling. "You know, it's not impossible for them to have natural children" he pointed out. "I thought males were supposed to be able to have kids permanently? And Chris did have a rejuvenation in the future just before the wedding. Doesn't that increase fertility as well?"

"Indeed it does" Doc agreed. "They even warn you about it at the clinic. I didn't pay any attention to the warning at the time because I didn't have any plans for marriage, but now that my counterpart has gotten married, it might be interesting to test the idea. It's certainly not inconceivable that Susan could end up getting pregnant."

"That's a really weird thought" Mike muttered. "Dad and Mom having a baby? After all, we're seventeen. Of course we were adopted, but even so, I would still feel awkward about it."

"What about us?" Marty agreed, pointing at himself and Calvin. "We knew Doc as a bachelor all our life. Him having kids at his age… no offense, Doc, but it sounds so strange that I can't wrap my head around it."

"I can't blame you, for I'm having trouble doing that myself" Doc said. "Well, let's stop clogging my counterpart's hallway. After all, it doesn't look like he and Susan are going to be here yet any time soon."

The others agreed, and as they went into the living room, a smile crept on Calvin's face as he noticed Ann. Although he knew that Ann wasn't exactly another Jennifer clone he could just date, he certainly liked her. In fact, he was paying even more attention to her than to the real Jennifer, who was sitting right next to her. Of course, there were slight differences between the two. Jennifer wore her hair slightly more conservatively, and was in general soft-spoken, moderate and nice. Ann was similar to her, but was slightly brasher, harder and more cynical. That survival mentality she had carried from 1985-A, and was even stronger present in her than in Claudia, despite the fact that she had been the one forced to strip at the Pleasure Paradise. It attracted Calvin to her as he knew the feeling somewhat, considering that all had not been well in the Twin Pines timeline either. For that same reason, Marty continued to prefer Jennifer.

Trying to clear his mind, Calvin took a seat next to Ann and Jennifer. "Hi" he greeted them. "Have you been here long yet?"

Ann shrugged. "Perhaps twenty minutes. Jen wanted to help prepare the welcome party, and I wasn't inclined to disagree with that. She and Claudia baked a delicious cake together, while I put the strings up."

"I see" Calvin replied, looking up at the ceiling. "Well done." Ann blushed at that, and Calvin felt oddly shy as well. "I hope they'll be here soon" he finally settled upon. "Although Doc thought it might take a while yet."

The inventor nodded. "Presumably, yes" he said. "It's, let's see, 9:46 now, and the last time I checked they were still at Sacramento airport. And it's a long drive back to Hill Valley from there, I can assure you."

"Yeah, I know" Marty replied, also taking a seat. "So, you think they won't be back until 10? After 10, even?"

"I'd estimate the probability of them being here before 10 AM to be under 20%" Doc said. "The most likely time for their return is 10:10, but perhaps it might be 10:15. Wouldn't want to get your hopes up early."

"Good point" Mike agreed. "Well, in the meantime, how about we fetch you something to drink? We've got everything except alcohol, because after seeing what it does to Dad, Claudia and I decided not to try it either. Not to mention what it did to my, well, my previous mother. And of course, we're underage."

"I see" Calvin replied, shuddering as he thought of his own mother in the previous timeline – who hadn't been as bad as she had been in the timeline Mike and Claudia came from, but even so. Thankfully, new Lorraine was much less inclined to go for the bottle when in distress.

Claudia nodded. "So, how about a cup of coffee to start off the morning? I know it's early, but I've seen you both yawning, Marty and Calvin."

The twins blushed. "Hey, I can't help it that I've got a hard time waking up early" Marty defended himself. "I just really like my bed. And Calvin hasn't been sleeping very well this week anyway, so I can't blame him either."

Mike smiled. "Just kidding. We'll fetch some coffee – and tea, of course, for who would prefer to have some of that."

He was just setting off for the kitchen when the familiar sound of the door unlatching could be heard. All inhabitants of the room froze, and Claudia turned to her adoptive brother with an icy glare. "Michael Emmett Brown," she said, "didn't you lock the door after we let everybody in?"

"Of course I did!" Mike exclaimed, offended. "I'm sure of that!" Cautious, he took a few steps towards the door.

"You might be, but I keep the spare keys on me at all time and know every password" a familiar grave voice sounded in response. The identity of that person was confirmed when he stepped into the room. "Hi, everyone – we're back."

"Dad!" Mike gawked. "I thought… Doc just told me you couldn't be back until 10:10!"

"No, I said that the probability for them being back before 10 AM was rather low" Doc corrected. "But Mike does have a point, Chris – how come you're back already? I figured you were still halfway to Sacramento."

"You can blame that on Susan" Chris replied, grinning and hugging his adoptive son. "At the end of the trip, she tripped in the airport over some uneven patch of pavement. She came out all right, but the heel of one of her shoes broke and her dress was ruined, and she was feeling a bit embarrassed to face you like that. Since it was still our honeymoon, I proposed to buy her a new set in the Sacramento of the future, and after we did that, we got the idea of flying over to Hill Valley and coming back a little earlier, just to surprise you."

"You certainly surprised us, Dad" Claudia agreed, hugging him as well. "We didn't even hear any sonic booms."

"That's because we broke the time barrier over Clayton Ravine, and then drove over here" her father explained. "I'm not that reckless. Even with the relatively secluded nature of our house here, it's still not perfect, and people might see. I would have preferred an even more secluded place to live, but that was unfortunately way out of our price range."

"Exactly" Susan confirmed, walking in. Calvin saw she was wearing a beautiful dress that could only come from a time beyond theirs. "What do you think?"

"You look great, Mom" Mike complimented, hugging her. Claudia did the same.

"Well, this is something only you could come up with" Calvin remarked, standing up to shake Chris' hand. "Time travelling back just to surprise us at the party?" He shook his head. "With time travel in your life, you can never reasonably expect something anymore."

"Well, it has benefits for the user" Chris grinned, firmly clasping Calvin's hand before the latter went on to Susan. "After all, you never have to be late for an appointment. Of course, I wouldn't recommend using the time machine like that. As you know, it's extremely dangerous to recklessly hop around the space-time continuum without regard for its safety and… are you all right?"

That direction was directed at Calvin, who was standing still in the middle of the room, finding himself suddenly unable to move. He could think of the command to move his leg, but the limb simply remained where it was. What was more, he felt a numbness enveloping his brain and black spots danced in front of him.

"I'm… not sure" the teen groaned, finding it difficult to speak. "I've been… having trouble sleeping for a while… but… this is new. I'm feeling… sick."

"You should sit down" Ann advised, worried. She stood up and held his hand. "You can sit down, can't you?"

"I'm not sure" Calvin admitted, blinking as his vision remained blurred. By some lucky chance, he then gazed at his numbing arms, and suddenly paled. Was he mistaken, or did he just see through his right arm?

He wasn't mistaken, the teen decided, as Marty and Jennifer, who were sitting on the right place to notice it, also gasped. Nevertheless, his vision rapidly weakened, as did his state of mind. "I…" he groaned. "I, I think… I… am going… to…"

He wanted to finish with 'faint', but couldn't make himself say the word. Calvin tried it three times, and finally gave up after the third time. The next moment, everything went black before his eyes and he passed out.