"Here is the collection of Ancient gadgets Stackhouse's team was able to get at market," Radek said as he plopped a box down on the papers strewn over the other half of Meredith's desk.

"Oh, isn't there someone else? I don't have time to wade through the Ancients' wacked-out versions of children's toys."

"Nobody gets to touch these until we give the okay. Your rules. Also, is your turn." Radek chuckled in an altogether disconcerting way.

"That's creepy, you know," Mer called after him as he made his escape. She sighed and turned to the box, gingerly picking out the broken and dead contraptions and opening their catalogue of Ancient tech to update and cross-reference their new batch. It was getting late. Maybe John would come save her before she got to the point that her brain melted from the mundanity of it all.

It took a moment for what she was seeing to sink in. It wasn't so much the same device that had gotten her here as it was the complement to it. Once that occurred to her, it was obvious they were supposed to be used in conjunction with each other.

After few moments of blankly staring at it, she dropped it like it was burning her. It landed on the desk with a heavy thunk.

Mer still didn't know what exactly it had done, but she had her life back, and she wasn't sure she was ready to face whatever the device meant just now. Her brain cycled quickly through the possibilities. She could toss it, hide it, blow it up. Did she ever want to see it again?

She knew what she wanted to do. Attach some C-4 and shoot it out the window. Watch it blow up in the darkening sky. She growled in frustration because she knew she would never do that. She had to know.

She reached out carefully and turned it slowly, looking for identifying markers and traits so she could refine her computer search. While she was taking all this in, other things were making themselves obvious to her. This part was in working order. Seeing this half of the equation made the buried memories come back, and she knew that - whoever she had been back then aside - what she remembered of the device wasn't quite right in comparison. The other part wasn't right. It wouldn't have worked right.

But that only brought more questions. If this was what happened when one component wasn't in full working order, then what was supposed to happen? And how could she possibly fix it with only the one half in hand, while still not sure what the extent of the damage had been?

It wouldn't matter how long she studied this, months or years; in the end it would still be a bit of a leap. All she wanted was her memories back. She'd just gotten her life back under control and she just wanted everything to be normal. She was happy. Would she be able to handle it if there was more to this?

The sound of boots moving across the lab floor snapped her back to the present. She fumbled the device and managed to slide it away, tucking it among the other things littered on her desk, before looking up to see John biting his lip to stop a smile.

"Looks like a long night. I brought you coffee."

Mer reached out and snatched the mug, holding it under her nose and inhaling. "Oh, thank god. I love you."

"What's disturbing," John said, sliding onto the stool on the other side of the clutter, "is that I can't tell if that's for me or the coffee."

Mer took a few gulps before answering, "Maybe you're right. I think I'd like to be alone with strong, dark, and delicious here."

John held up his hands in a mock peace-keeping gesture. "Who am I to stand in the way of true love?"

She set the coffee down and looked at the mess that was her desk, carefully avoiding letting her eyes linger on the complement device. "Thanks."

"No problem," John shrugged and changed the subject. "Well, it's getting past my bedtime and you know I can't go to sleep without a good night kiss."

Mer looked at the clock at the edge of her computer screen. It was nearing midnight already and John was an early riser, but she'd gotten used to him being deep in sleep by the time she made her way back to their quarters. "I hadn't realized. Sorry."

"Just don't fall asleep on your keyboard again. I think you broke Zelenka's brain. He couldn't speak English for a week after fixing the equations you messed up rolling around in your sleep."

Mer smirked. "That was funny."

John got up and wrapped his arms around her. "No, that was cruel."

She shrugged. "You going to bed?"

"Yeah."

"Okay." She tilted her head up so he could lean over her and give her a sweet kiss that made her wish work would just disappear so she could leave, too.

"Night."

"Night."

John stopped at the door. "Meeting at 0900 tomorrow, don't sleep through it."

She waved her hand in acknowledgement and turned back to the computer. When she was sure John's footsteps had receded, she drew the complement back to the forefront. She hated the thing, but there was a lot of work to be done if she had any hope of putting all this behind her for good.

...

Figuring out the workings of the complement device took a few weeks, but she had to work in secret. Mer wasn't ready to say or do anything that might damage all the ground she'd finally gained with her friends and co-workers. It was hard work acting normal when every day her suspicions that this was worse than she had thought held more weight.

Mer had taken on a project for which most of the work needed to be done at night so that she was never in bed at the same time as John. She didn't want to give him up, especially when they'd just been getting back to normal, but she knew she couldn't keep going like before, not when her suspicions were coming back in full force.

With the new parameters the computer had turned out a database entry within the first week. The words 'alternative dimensions' written in Ancient were nearly enough to make her want to get rid of the device all over again. Mer wasn't sure she could stand to lose this - it was her life now, and yet it turned out that fading memory of what they all believed had been a figment of her broken mind might be true.

She tried ignoring it, because she wanted to stay, but now that she knew the truth she couldn't bring herself to do that any longer. She hated it, wished she could keep this life, but it was turning out that this life wasn't hers to have, it never had been.

The memories she'd buried over half a year ago were suddenly brought to the forefront of her mind and it was like walking on glass. Her stomach clenched at the thought of losing her life all over again.

John stopped by their quarters one day and found her, not asleep as she had recently taken to being during the day, but crying steadily into her pillow. He made a distressed noise as he climbed behind her and pulled her into his arms. "Hey, hey, I got you. What's wrong?"

He clutched her tighter as his words only seemed to make it worse and tucked his nose into her curly hair, rocking her gently.

Mer wasn't strong enough to pull away from him, she couldn't refuse herself the comfort of his arms, and slowly the tears dried up.

"You okay?" John said softly, voice muffled where his face was still buried.

This wasn't right, however much it felt that way to her. For the first time in her life she wanted to continue to live in ignorance, just be his Mer forever. But she wasn't, she really was Rodney, and Rodney had a home. She had trouble thinking of Rodney as herself anymore but she knew she couldn't keep him from it.

She fit so much better here. It was peaceful and she had full life with friends and family, no crisis of the week, all the theoretical work she could handle, and John. Rodney had a John as well. But Rodney was an idiot who'd never considered, never seen, how much John meant, and she didn't want to be that Rodney again. It was possible Mer had made it to Rodney's body back in the other reality, but that Atlantis would have believed her at some point. They would have been looking for a way to fix it, and the bottom dropped out of her stomach at the thought of what it must mean that all this time had gone by and they hadn't been able to.

This wasn't a matter of what she wanted, and she'd never liked being noble but she hated it right now. This was a matter of where she belonged. Rodney belonged on the other Atlantis and this John deserved to have the real Mer back if he could.

Mer pulled away from John, ignoring his concerned noises for the moment and gathering herself together. She sniffled loudly and wiped the tears from her face.

"Mer?"

"Not now."

"Mer, just talk to me."

"John."

"Please. Don't shut me out, Mer."

Mer forced herself to meet his eyes. "Later."

John looked ready to argue but she cut him off. "Later, I promise. Just give me time. Please, John.

He sighed unhappily but nodded. "I should probably get back to work, anyway."

"Yeah."

"You gonna be okay?"

She didn't have anything to say to that so she pretended she didn't hear him and locked herself in the bathroom. She could hear John's sigh and his thumping around the room for a moment before the door swished open and closed and he was gone.

...

"Radek, I need your help."

Radek's eyebrows were drawn together in disbelief as he stared at Mer. She rolled her eyes and moved closer, whispering furtively, "Seriously. I mean, I could totally do it by myself but I'm kind of on a timetable here and I could use your help."

Radek tilted his head to the side. "You will acknowledge my assistance."

Mer nodded. "Absolutely, you can have all the credit."

Radek pulled back, wide-eyed, and Mer hastily waved it away. "Later. It will all make sense later, okay?"

It wasn't as if she'd be around for the Nobel on this one, and she never could have accepted it in Meredith Sheppard's name, so why not throw Radek a bone.

"Also, you will share your coffee stash."

"Okay." Mer nodded. "In my private lab at 0800."

"The good stuff," Radek hissed after her, obviously deciding to take advantage while he could.

...

John, Elizabeth, Carson, and Kate were standing at the back of the room watching curiously as Mer and Radek buzzed around the contraption they'd built. There was a viewscreen in the center of the room over the main console. It was connected to a small hand-held device that they'd discovered their second year here. It had similar properties to the quantum mirrors but required precise directions to function and only provided a small visual as far as they'd been able to tell. It was interesting from the theoretical standpoint but entirely too much work for any kind of everyday use and so had been quickly set aside for other work. This was in turn attached to another small device, completely standard-looking, nothing special that any of them could tell.

Radek held a tablet and was going about the process of turning everything on when Mer moved to a position in front of the center console.

She cleared her throat. "So, this is going to be hard to hear, god knows it's taken me weeks to absorb, but I need you to hear me out."

She motioned to the inconspicuous device on the table. "This is one half of a system designed to allow mental travel between realities. Together they would transfer a person's consciousness from one body to their duplicate in the reality selected, while doing the same to the duplicate. As the devices are not identical, but appear to be two halves of a whole, I believe the consciousnesses would have had an awareness of each other and the ability to share information."

"Are you saying this is a bodyswapping device?" John asked, half interested and half horrified.

"For intelligence gathering?" Elizabeth added, doubtfully.

"I—" Mer swallowed, preparing to take a huge leap, "This is how I got here."

Radek stepped in, "From what Meredith tells me, we have come to the conclusion that the other piece was defective. We have been unable to establish a complete connection with it. We have, however, used the connection this part has to tap into parts of the alternate Atlantis."

He tapped something on the tablet and a selection of security camera views popped up on the viewscreen.

Carson, Kate, and Elizabeth were all leaning in to stare at the screen, but John held back, eyes flickering between Mer and the images.

"Why do you think you came from here?" Kate asked, "Why should we believe you now?"

"I can prove it." Mer said. "Radek?"

He cut one screen to a room almost identical to the one Teyla inhabited here and zoomed in on a photo hanging on the wall.

Elizabeth gasped first, looking from the photo to Mer, "that does look remarkably like—"

"Me."

Another screen changed to show a copy of the death certificate Radek had found two days ago.

"But, he's dead." Carson stated.

Mer nodded, "look at the date."

None of them said anything. They all knew what had happened that day.

After a long, loaded silence Mer cleared her throat and gathered herself up with one last glance at John. "When I first arrived I had no way of proving what I knew, and there was such a feeling of familiarity here that I came to question my sanity as well."

Carson shot her a guilty took but Kate was still absorbed in reading the death certificate.

"So the alternate reality version of Mer -" Elizabeth gazed questioningly at Mer. "Rodney. If he's—Well, where is Mer, I mean, the real one?"

"Well," Mer said, "like I said, I think there's some connection between the people who get swapped."

"You- You been communicating with Mer the whole time?"

John's eyes had narrowed and he took a menacing step forward, but that broke Elizabeth from her shock and she put her arm in front of him. "Wait, John." She looked back to Mer, "but Rodney's dead, right?"

"That not…" But Mer wasn't really sure how to finish the thought.

John made a choked noise, the mask slipping.

"But I think she's still somewhere, she not completely gone. The way I felt comfortable here, how I knew what to do in this body without any real trouble … well, I thought it was an indication that you all were right, but I think now that it means she's still around. The only place that makes any sense is the other device. It wasn't working so it couldn't transfer her into my body but that doesn't mean she just disappeared, it's probably holding her consciousness somehow."

"So she's been, what? Unconscious this whole time?"

Mer and Radek exchanged looks. "She is unlikely to be aware of anything, yes," Radek said.

"Then activate it again!" John said. "That's Mer's body, you can be stuck in the device. Switch again!"

Mer backed away. "It's not that easy, John. I- I would. If I could. But it only worked last time because it was activated on the other end and the device wasn't working properly. The safety protocols should have stopped it. This one is working, and it's not going to let me activate the process. John- I'm sorry."

John looked ready to hit something but instead he whirled, fleeing the room.

Mer looked at Elizabeth. "I'll do what I can on the other side, try to get her out of the device. I'll figure something out. I won't give up."

Elizabeth and Kate turned sharply to face her. Elizabeth spoke first, "the other side?"

She nodded, "We also figured out a way to connect the transporter mechanism to the mini-mirror. Cascade failure would make it impractical for anyone else but I shouldn't have any problems."

"You're leaving," Elizabeth said flatly.

Mer nodded. "I can't stay. They need me over there." With a glance at the door John had disappeared through, she added, "and I don't think it's a good idea to stick around."

Carson looked at her sympathetically. "You should say goodbye at least. He deserves as much."

"I know."

Radek was hovering inconspicuously, turning everything off in anticipation of reconnecting the mirror to the transporter they'd rigged up.

"You have time," Kate said gently.

"No, I can't stay now. I have to leave. Just give me a few minutes." Mer set down her tablet and left the room.

...

John didn't know what to do, what to think. He was sitting on their bed staring blankly into space when Mer forced the door to their quarters to let her in. She stopped just outside their bedroom door.

"I didn't mean to make this harder on you. You've put up with so much from me."

"Twice. This is twice you've taken her away from me."

Mer leaned her head against the doorframe. "It's been me the whole time. I just didn't know."

"I need time."

"I'm going back."

This caught John's attention. He looked at her disbelievingly. "What?"

"Radek and I, we figured out a way for me to go back."

"What about Mer?"

Mer shook her head, "I'll try, John, but there's only one body. I have some experience with this kind of thing but it will take time. I'll get her back to you."

John let out a shattered breath, closing his eyes as his head fell.

"I'm sorry." Mer whispered.

John didn't respond.

"I wasn't faking it," Mer whispered. "You deserve to know that. I do love you."

When John continued to ignore her, Mer turned and exited their apartment for the last time.

...

There were tears in Carson's eyes as he sat between Kate and Elizabeth, all of them still too stunned to say anything. Mer wiped a hand over her cheeks when she entered the room. "Come on."

"It's ready," Radek said.

Mer stood where the beam would go, nodding stiffly and bringing her hand up to her face again. "Just do it."

"Goodbye," Radek said.

Mer sniffed. "Don't. But- thanks. You know."

Radek nodded and Carson sniffed in the background.

With a final nod Radek put his finger on the tablet and pushed the button.