A World of Difference

Author's Note: Starts slowly, with some definite science-fiction elements throughout. If either is not your cup of tea, I'm sorry. I'm sure you'll find other stories here more to your liking.

Disclaimer: All sexual activity described here is between fictional consenting adults. Certain real life people are mentioned in the story, but their actions are fictional as well.

~~~~~

This is the convoluted story of how I met my sister-me, and how we wound up married to one another. You're probably already thinking, "What the fuck?" Just read, and if you still want to judge, you can.

My name is Steven Mobley and I was born April 19th, 1994 in Denver to Jim and Catherine Mobley. I had what I suppose is a pretty ordinary childhood as an only child.

Yes, only child. But you're saying, "You just said you have a sister." I do, sort of. We just didn't grow up together, and you would never guess why. It will get clearer soon, I hope. Or it will give you a frigging headache.

I graduated from East High School in Denver and then went to Boston University, where I majored in Mechanical Engineering. I was offered a job interview for April 22nd, the same week as my birthday, with a scientific research company in Burlington, a city north of Boston, called Carlson Labs. I wasn't really looking to relocate to Boston permanently, but I knew they also had offices near Denver and several other cities, so I went to the Friday afternoon interview, hoping I could eventually transfer back home, if I got the job.

Dr. John Wilkins met me in the lobby. "Hello, Steven, we're so glad you could make it. Come on, we've got a lot to talk about." He walked me to a conference room, where three other people were already seated, and a PowerPoint presentation titled "The Bridge Project" was being displayed on a screen at one end of the room. The two men were introduced as Dr. Bruce Gower and Sam Tucker. The third person was a beautiful, skinny brunette who looked eerily familiar, about my own age, who was only introduced as Stephanie, while they only introduced me as Steven. I thought it was a bit strange that they didn't mention either of our last names, but took a seat next to her.

Dr. Wilkins started in on his presentation. "The two of you have both been invited here under the pretense of a job interview, but that was a ruse. The real reason you are here is that without knowing it, you are both critical to a research project here that has been going on since before you were born. Let me explain."

He advanced to the next slide, which showed two Planet Earths, side by side. "Physicists have long theorized that any time multiple outcomes are possible for an event, all of those outcomes actually happen, each one producing a slightly different version of the universe, separated by a short distance in a multi-dimensional space. The Bridge Project was our lab's attempt to create a portal between our world and another parallel Earth."

He advanced to the next slide, showing a bridge between the two worlds, then to another, which had a photo of a rectangular frame in the middle of a large room, with a shimmering surface spanning it. My mind immediately went to the Stargate series of movie and TV series.

Dr. Wilkins continued, "On July 30, 1993, we opened the portal, and all of our instruments showed that things were working as expected. Two researchers stepped through the portal's energy field, yet we saw them come out the other side, as if they hadn't gone anywhere. They walked back through the portal in the opposite direction, and we were sure there was something wrong. They walked through one more time, and walked around the frame to enter it again, and this time the energy field stopped them. We were talking things out, when the same two researchers walked back out of the portal, so our world was the first to to have two duplicates, and has been known as Earth 1 ever since. It was actually the Earth 1 researchers who had decided to come back the way they came, while we were unknowingly engaging in a conversation with their Earth 2 counterparts. We had succeeded, but we connected to a world where not only did our lab also exist, but it was working on the same problem, and had succeeded at the same moment."

"My Dad used to read superhero comic books that talked about an Earth 1 and Earth 2 that were parallel worlds," Stephanie said, as I remembered my Dad telling me about the same comics. "It's amazing that it's actually real, but what does it have to do with us?"

"I'm getting there, Stephanie," Dr. Wilkins said. "As the next several days passed, we determined that the two worlds appeared to have identical histories, certainly right up to the time of our experiment, and were following the same trajectory, initially. We were afraid that our bridge may have actually caused the split, so we began looking for any differences at all preceding its activation. The two worlds have diverged gradually since then, as other outcomes have differed. And to our surprise, a large cluster of differences actually developed around Denver or people from there, more than from here. It has taken us a long time, but we are now 99% certain that the differences there center originate with the two of you."

I blurted out, "Us? How? I don't even know Stephanie."

"You wouldn't, that's the point," Dr. Wilkins answered. "She's from Earth 2, and only Earth 2. She doesn't exist here, and you don't exist there. You see, you are both children of James and Catherine Mobley, born on the same date but on these two different versions of Earth. You were the only divergent births in the first 15 months after we opened the portal, of any nation where we have been able to compare the records. Given your birthdate, we think you two might have been conceived shortly before the bridge was opened. We believe you are two of the possible outcomes of what was essentially the same moment of conception. One egg, surrounded by many sperm, and a different one succeeded in fertilization in each world, perhaps even being the creating event for the two worlds. It will take a DNA analysis to be sure, but we believe that genetically you are in between being identical and fraternal twins, sharing the exact same genes from what had been a single egg, but half matching, half not, from your fathers' sperm, so we would expect to see approximately 75% of your genes in common, instead of 50% for normal siblings."

"You mean Stephanie's genetically my sister? Or is she a female version of me?" I asked, staring at her. She looked just as surprised as I was, but there was also caution on her face. No wonder I thought she looked familiar, I could see the resemblance to the Mom of my childhood, now.

Dr. Gower said, "It's actually in between those two things. It's not as simple as saying that she's genetically identical to you except she has an XX chromosome where you have an XY. On every one of the 23 chromosome pairs, one half should be identical, coming from your mother, while the other half varies as a normal brother-sister pair would, including the X/Y difference. The same thing could have happened as two females or two males, and probably did, on other parallels."

I chuckled, on the edge of nervous giggling, saying, "So I have a half-sister, half-me? A sister-me? Shit, my parents will freak out!"

I saw tears start to come to Stephanie's eyes, and I immediately like I'd caused it, but didn't know how. "What's wrong, Stephanie?"

She wiped away a tear, and took a deep breath, before softly saying, "My parents both died, last November. And now you're telling me yours are still alive, and I'm somehow the difference that got them killed? My god, can I see them?"

Dr. Gower said, "You could, if we are able to go public with the project. Before we can do that, we need to determine one thing, and that's why we needed to bring you both here, including bringing Stephanie through the portal so you could be in the same world to meet, to understand all this. While we know that you two appear to be the earliest divergence between the two worlds, we need to determine precisely whether your conception was before or after our opening of the bridge."

Dr Wilkins continued, "It is the difference between our portal bridging two worlds which had only recently split, but would have still been separate without the bridge, or being the wedge which split one world into two, possibly weakening them both. In addition to the DNA testing, we need to perform some recently developed age tests on your cells to determine if your conception occurred before or after our test, and by how much time. If your conception occurred before, then it would be safe for us to continue opening new portals using higher power to reach worlds with greater divergence, but if it was after and we caused the split, we will be closing the portals forever, and you'll need to be back on the other side of it, Stephanie."

I thought back to a conversation I had with my parents. "My parents told me once that they first made love the night of Mom's 19th birthday, which would be July 28th of that year, and didn't again until after they knew she was pregnant and decided to get married, so conception must have happened from that first time, but I know that doesn't tell you exactly when the sperm met the egg. Of course, if they had made love after the bridge opened, we wouldn't need the test."

Dr. Gower said, "We know, your mother's obstetrician recorded the same thing being said by your parents, and based her due date on that, in both worlds. If that record had said intercourse had been a later date, or even different dates in the two worlds, we would be looking at what might have happened differently in the days leading up to that. We still might, if it turns out your conception was after the portals opened."

Stephanie said, "I'll consent to the test. On one condition. The results of any DNA comparison between Steven and I must be completely confidential, and our identities not released to the public in any way. If my parents are dead in my world and not this one, how many others have had negative outcomes that turn out to have happened in only one world that they might try to blame on us? We'd be targets for them. No thanks. Let them think it's all due to randomness and quantum physics, which is the truth anyway. We will need signed statements to that effect, from the labs on both worlds."

"Of course," Dr. Gower said. "Medical information is protected by identical laws on both worlds. We will not reveal anything about either of you to the public, we are primarily running the DNA analysis to prove you indeed came from essentially the same egg, then the aging analysis so we can make a decision of whether the labs try to build new portals to link to additional Earths. We will get started on those confidentiality agreements. In the meantime, I would expect the two of you have a lot of questions for each other."

"I consent as well," I said. Although I did wonder how they got access to those obstetrician records, if they're supposed to be protected by law.

The three men left, and Stephanie and I stared at each other for 30 seconds, before I said, "Hi, sister-me."

This brought a smile, and she said, "Hi, brother-me. So, besides our gender, what else has been different in our lives? Are you an only child, too?"

"Yes," I nodded. "At least until today. Now I've got a twin sister." I took her hand and squeezed it.

"Sports? You look like an athlete," she said.

"Baseball, high school and college. Weightlifting to build my muscles, the usual stuff, I guess. A little JV basketball, although I rode the bench a lot, and didn't make varsity."

"Dance and track," she said. They had both done great things for her body, but had not added bulk to her like my workout routines had. 'God, this is my sister I'm thinking this about!' I thought.

"I'm going to Arizona State right now, nursing program," she asked. "How about you?"

I answered, "Boston University, on a baseball scholarship, Mechanical Engineering major. Best friend back in Denver?"

"Amy Sanderson. You?" Stephanie said.

My eyebrows went up. "I actually lost my virginity with Amy, and took her to Senior Prom, but we broke up over the summer before college. My best friend is Scott Jimenez, even today." Amy and Scott were the closest neighbors my age growing up, and I expected they were Stephanie's, too.

Stephanie laughed. "I dated Scott. He wasn't my first lover, but after he and Amy both went to UCLA, they started dating, and are engaged to be married. God, this is so weird."

I smiled at her, saying, "My Amy went to UCLA, too, but in my world, Scott never got involved with Amy at all, because she used to be my girlfriend, and he and I both went to BU, and he's my roommate. We really have caused changes in the two worlds, just by being different genders."

We compared notes for a while longer, getting closer as we did, and she told me the story of her parents dying in a car accident near Santa Fé, when they were on their way to Homecoming Weekend at Arizona State. Mine had only come to BU once, when I first toured the campus, because of the distance. They already had their plane tickets for Graduation. Maybe simply our choices of college changed their fates. No wonder Stephanie was so upset about it.

Finally, I asked, "So, why all the concern about the DNA analysis? They already think they know the answer."

"Because of Mom and Dad, silly," she said.

"What about Mom and Dad?" I asked.

"Oh, wow," she said, surprised. "Yours haven't told you?"

"Told me what?" I asked, not sure I wanted to know. "What kind of secret are you talking about?"

"Okay, brace yourself," she said. "Mom and Dad are actually brother and sister. They were living with our grandparents somewhere in New England when Dad got Mom pregnant that first time they had sex, and they chose to move to Denver where nobody knew them, so they could live as husband and wife."

I couldn't believe it for a while, but it began to make sense. How they both said they were only children whose parents were all dead, how they had no childhood memorabilia or any photos from before I was born, no childhood friends mentioned at all. Accepting that Stephanie had no reason to lie to me, I asked, "So, the DNA comparison is going to show us as even more related than Dr. Wilkins expects, is that it?"

Stephanie nodded, and said, "Yes. Normally, the test for siblings will show that half of the DNA that I got from Mom matches to the half you got from her, and the same for Dad's DNA, with the exception of the Y chromosome. With the identical egg, all of Mom's DNA will match, while we would still match on 50% of Dad's. But with Mom and Dad being siblings, not only will half of the DNA I got from him match to what you got from him, except the Y chromosome, it will also match half of Mom's DNA, too. If that's the result, it will be blatantly obvious to any geneticist that our parents are closely related, and committed incest. Your Mom and Dad need us to keep that quiet on this world, certainly, although it's even an issue of reputation for me in mine."

"So how did your Mom and Dad come to reveal that to you, and mine didn't?" I asked.

"I don't know why yours have never told you, of course. For me, it was after I climbed into bed with Dad one night after I turned 18, and pretended to be Mom, so he'd fuck me," she said, not even blushing. "He's the one I wanted to take my virginity, even if I had to trick him into it."

"You had sex with my... your... our Dad?" I asked, even more stunned.

"With my Dad," she said. "We really need to think of them as different people, at least as different versions of the same people, at least a little different over time, because I'm sure your parents' experience of raising a son couldn't have completely paralleled my parents' experience raising a daughter. I mean, I'm sure he taught you to throw a baseball, but for me it was Mom enrolling me in dance classes. I bet if we looked closely, they also made different friends over the years because of us attending different functions, and so forth, and changes rippled through Denver as a result. So, I haven't had sex with your Dad. Not yet, anyway."

"Whoa. You're going to tell me you want to go after my Dad, too?"

"If I get the chance, yes," she said. "Unless raising you instead of me has changed him that significantly, he's still going to be gorgeous to my eyes. And since he does share the same history of incest with mine, he ought to be fairly comfortable with the idea, especially since he wasn't the one who raised me. Mine didn't even yell at me after I tricked him, and that's when he and Mom revealed their own past, and I wound up in bed with both of them. Were you ever attracted to Mom?"

I was reeling, and said, "Attracted, yes. She's hot, and I can understand why Dad would have crossed that line. I even had a few fantasies about it. But I never took it further than that."

"Would you like to now?" Stephanie asked, grinning wildly. "After all, if I go after your Dad, you ought to go after your Mom, too. Maybe you and me, too, brother-me. I saw how you were looking at me before you knew who I was, even a couple of times after. You're just what I imagine Dad was like at our age. I don't know how not to be attracted to you."

She leaned slowly towards me, and we kissed, tenderly at first, and then with more passion. We pulled back from each other, looking the other in the eyes. Green eyes I suddenly recognized as my own. "Oh, my," Stephanie said. "That did not feel like I imagined kissing my brother would feel. That felt... like Dad did."

That's the moment that the three men re-entered the room, so we sat back in our chairs and faced them. They put two confidentiality agreements down in front of each of us, nearly identical, except for one minor wording difference, and a sticky note on one that said "Earth 1" and the other "Earth 2", as well as consent forms for the testing. In front of us, Dr. Wilkins signed the Earth 1 ones, and Dr. Gower signed the Earth 2 ones, and then Stephanie and I signed our respective forms. I noted that the agreements did not place any restrictions on Stephanie or me regarding telling anyone about the two worlds. I just didn't think anyone would believe me if I did.

I asked, "So, are there two Dr. Wilkins and two Dr. Gowers working at the two labs?"

"Yes, I'm the Dr. Gower from Earth 2, and I'm the Director of the Lab over there, and our Dr. Wilkins is Assistant Director. While the opposite is true for Earth 1. And just so you know, we're PhDs in Physics, not MDs, although we also employ PhDs in History, too."

"And how about you, Mr. Tucker?" I asked him.

"I'm the Chief of Security for the Earth 2 lab," he said. "It's part of my job to control who gets to pass from Earth 2 to 1, so I brought Stephanie and Dr. Gower over, and I will be bringing them back, if the decision is made to close the portal. I was hired ten years after the portal was opened, and only by that lab, when they stopped trying to keep the staffs identical and my predecessor on Earth 2 quit, while the Earth 1 one didn't for another two years. I've never met my counterpart on Earth 1, but I understand that he went into politics after the job he got instead of this tried to bust the union that was there, and he's actually running for U.S. Senator for New Hampshire, now."

"I thought you looked familiar," I said. "So your counterpart is Congressman Tucker from Nashua. Very interesting."

"What if I decide I don't want to go back to Earth 2?" Stephanie asked. "After all, my parents are still alive here. As close as I'm going to get, anyway. I have no other family back on Earth 2. If I wanted to build a relationship with the Mobleys of Earth 1, why shouldn't I be allowed?"

"Fundamentally, you don't belong here, Stephanie," Dr. Wilkins said. "There are no records of you anywhere here. Your driver's license, your bank cards, your cell phone, even the diploma you're working towards, would all be worthless here. Your Social Security number is the same one Steven has, we checked. As far as the U.S Government is concerned, you would not even be a citizen here, you'd be an illegal alien."