(Author's Note: BOOM! Seven thousand words: even! Hopefully this'll whet your appetite before the next chapter, which I've already started in anticipation of this month's crazy business for me. Maybe we'll finish this fic by Christmas? I love you, Jell-O Squares! It's gotten to the point where I recognize some of your personalities in those reviews and I look forward to hearing from each of you! Thank you for sticking with me. Enjoy! -Doverstar)

It was cold in the sewers.

This was favorable if you were plotting dastardly deeds; it helped to get you in the mood. The walls were cold, the ground was cold, the colors were cold, and of course, the sewage itself was freezing. You didn't get sunlight down beneath Central City, just rats and generally-bad smells.

The cold was welcome to him, to the mind behind the chaos above, but the same could not be said of Mick Rory.

Rory appeared to hate the cold. Well, he would, wouldn't he? Apparently, he had been a pyromaniac before the particle accelerator had made him all warm and fuzzy inside, and being down in the old 'underground lair' was dreadfully against his nature. Almost zero heat at all down below the city, and it never failed to put the homely-looking pawn in a sour mood. He wasn't clever enough to know how to work a toaster, let alone steal a heater for his own room—one that had been graciously offered, here in the underbelly.

When Rory returned to the cavern, his master was watching a small screen in the corner, plugged into one of the only outlets in the entirety of the city's tunnels.

"How did it go, mate?" called the lean figure perched near the television. He could hear Mick jump at the sound; clearly the pyro hadn't noticed him sitting there. Keep people on their toes. No one was truly entertained when they were comfortable.

Rory's voice was tired, held more gravel than usual. "On the news. See for yourself."

"I'm watching something just a touch more interesting," sighed his superior, standing in a backwards kind of way that made his shadow do some impressive choreography. "Only channel we've got, I'm afraid. You'll just have to answer my question the way intelligent people do—directly."

Rory blew into his hands, a slight glow flickering over his face. He now held a few tiny embers, keeping him warm. All over, his skin was tinged raspberry red. Smoke curled, just visible, out of his mouth. "Ashes. All I had to do was walk in." He grinned, showing teeth that badly required some kind of professional orthodontic treatment. "The whole place is a big pile of rubble in the middle of downtown. You shoulda seen the flames." He exhaled slowly. "Pure white. Glorious."

"So sad I missed it." He narrowed his eyes at the wistful expression Rory wore. "You didn't stay and watch, I trust?"

Rory spat, right on the ground, very near his leader's soft-soled shoes. Grumpily, almost like a child denied a second helping of dessert, he asserted, "No. Nobody saw me." He paused. "I could've done more. I could've burned them all. There wouldn't've been a cop left in this town…"

"But our quick little friend stepped in to save the day yet again." He nodded, sliding his hands casually into his pockets. Rory eyed the movement and grew stiff, wary. "Not to worry, old boy, I know all about his rescue mission. He was late. He had extra help, someone wearing elbow patches and frankly atrocious specs—and still late. I expected him to turn up just as it all went up in smoke, but unfortunately, he took his time."

Rory scowled. "What if he'd caught me?"

"Were you planning on being caught?" A dangerous tilt sharpened the edge of his tone. He looked Rory in the eyes, and the pyro became even stiffer.

Rory didn't respond, licking his lips, but after a moment he shook his head.

A broad smile sprang to his mouth. "I've got his name, you know. Savitar. I was looking in the wrong place. Don't think we'll be needing a gun to slow him down anymore."

Rory, clearly thrown by the change of subject, tilted his head. A blank look cast a film over both eyes and his jaw slackened. "What's that supposed to mean?"

"He's pawned the title from the Hindu god of motion." A hand flicked this way and that dismissively. "A proper name. Shame, I was really, honestly beginning to enjoy our little nicknaming game. Freak. Running man. It's been good fun."

"You knew he was gonna show up?" Rory took a step nearer, all shoulders and meaty hands. "He could've made me and you were just sitting down here in your creepy—"

"Now be careful, Sparky, if I didn't know any better I'd say you were cross with me." He showed his own teeth in a bigger grin than Rory's, putting some convincing, clichéd snarl into it. "You remember what it is to pick a fight with yours truly?"

Rory's eyes darted to his left wrist, but he was like rock again in an instant. His silence was submission enough, and the man standing across from him seemed to relax at the quiet, hands coming out of his pockets empty, to the pyro's relief.

"Yes, I knew he'd be there. Not soon enough to save the station, barely soon enough to save every squirming little pedestrian, but honestly—did you think he'd miss it? You were live on television, Rory. How did those fifteen minutes of fame feel, eh?" Without waiting for a response, he turned back to the screen, long arms twisting behind his back. "Not to worry! He's practically beaten already. The things I've learned, mate—he's really crushed where he stands." A too-loud laugh. Rory jumped again. "Simply follow orders, my friend; we needn't fret over the God of Speed any longer. Lisa did well."

"Snart?" snorted Rory skeptically. "What'd she do?" It was no secret that he and the talented young lady were rivals, hardly the best of buddies. Rory was too blunt, hot-headed, slightly insane. Lisa certainly wasn't all there herself, but she had enough mellow in her to clash with the pyro, and obviously carried a bossy streak.

His pawns didn't need to know every detail, everything he knew, but he could spare this. He could flaunt this. This was like juicy gossip, except it was better, because it would probably end with a dead body somewhere and that was much more fun than whispers and obvious glances. It was worth it, spilling the beans. Just a little. They knew the overall plan, but he'd added something new—something that would remove the leather-clad hero from the picture. Should the need arise, anyway.

"She gave me a window." He tapped the screen jovially with one nail. "The speedster has a chip in his armor."

It hadn't taken too long to get Professor Stein on board the whole fight gas with gas train. The man was all but desperate for even the slightest change in his wife's condition, and drunk—but very intelligently so—on the hope of reviving her faculties altogether. Caitlin could relate; she'd experienced the same wild abandon at the thought of having Ronnie back from the dead the first time. But though it only took an hour to set the two scientists on the same page, Stein still had several problems with the theory.

The first thing he'd done, almost reluctantly—with a tone bordering on patronization—was to peddle out a list of reasons why this plan would fail. He'd produced copies of his Clarissa's X-rays on his phone, and while Caitlin studied the scarring around the air sacs, the deep-seated inflammation of her lungs, Stein began calculating on the glass demonstration board. It was only after he'd filled every inch of space with his scribbles that Caitlin understood where the disconnect had been formed.

"Professor." Caitlin had set the phone down on the white winding desk, taking up a rag to wipe away all his work, shifting her weight with barely-disguised excitement. And maybe a little pride. "We're not talking about an actual gas. Its construct will be…similar to that of a gaseous substance, but what it will actually be…" She abandoned the rag in favor of she and Savitar's calculations the night before, handing it to the older gentleman.

Stein's free hand flicked up to his glasses, as if he wanted to take them off, the way people did in movies when they were surprised. In the end, he chose actual 20/20 vision, simply gripping the paper tighter to contain his interest. He glanced up at Caitlin, gaping like a fish, only for a moment—but it made him look that much younger.

"It isn't a gas you're suggesting at all," he agreed, nearly breathless. "It's an absorbant."

"Something that we can release into her body's airway that will soak up the toxicity—"

"—and disappear altogether," finished Stein, just sparkling all over. "Barely a second after. Miss Snow," he said, finally taking the glasses off to better look her in the eye, "how is it that you and your friend were able to think of something so ludicrous, so

off-the-mark—something I never once thought of in four years of agonizing theories…in just a few months? And—" He actually chuckled. It was a grandfatherly sound, something that made him even warmer. "How is it that out of seven billion people on the planet, I happened to run into you at precisely the right moment in a coffee shop downtown? The very person who might end up saving my wife's life?"

He looked so made of amber and putty then. Glowing and soft. It was fascinating to watch a scientist—one with several awards—succumb to something like wonder.

"Coincidence?" she suggested, grinning.

Stein smiled back. "Science's mortal enemy."

This was what she'd wanted when she took the Hippocratic Oath. This was why she'd partnered with Dr. Wells, why she'd become a bioengineer, a doctor. For that look of pure light she was seeing on Stein's face, the look that said there was, in fact, hope. And she'd helped put it there, that fragile expression. At times like these, she thought even saving the day with the Flash couldn't compare.

She reached for her gloves. "Let's get to work."

Her powers practically gorged themselves on the chill in the air.

However uncomfortable the cold could make the human part of Caitlin, she knew without running any tests that the meta side of her felt right at home in the autumn wind. Octobers on Earth-66 seemed just as icy as the ones back home, and Killer Frost was relishing the bite of it. Caitlin knew she shouldn't have to worry as long as the snowflake pendant hung from her neck, but she tucked her yellow scarf a little more firmly around her shoulders, resisting the urge to make sure the necklace was still there underneath all the layers.

It wasn't that having actual superhuman abilities frightened her. It was the lack of control. If she'd just woken up one morning with ice in her veins, able to make it snow for Christmas Eve and never have another unbearable summer afternoon for the rest of her life—maybe even help Barry take down a few of the unrulier metahumans—that would've been fine. A big adjustment, a little stressful, but eventually she would learn to live with it.

The difference was that Barry and Cisco had come home from Earth-2 with tales of her evil doppelganger. A Caitlin Snow who was able and, worse, willing to harm others with the same powers. She'd tried to kill the Flash. A person in direct contrast to Caitlin herself. Earth-1's Doctor Snow. And now that she had these powers—thanks to Barry's misguided, grief-stricken trip into the timelines—all she could think was that they were, at their core, wicked. That she'd become just the same as Earth-2's version. That she'd want to hurt people and would only care about herself. Killer Frost was the physical manifestation of these abilities. She was every inch of the cold and bitterness Caitlin possessed somewhere deep down.

And she had already come this close to changing into Frost for the long run once. She was overly cautious about the chances of it happening a second time. Scarves and big black coats were a start.

Currently she was walking back to the bus stop, carrying takeout Chinese food in both hands. After a long morning of antidote-manufacturing with Professor Stein, she'd worked up a big appetite. Caitlin had just managed to convince him not to cancel his noon lecture in favor of the task at S.T.A.R. Labs. Real life still needed to press on, and the chemicals wouldn't be ready to test in a controlled environment until the next day. Any longer and she would've been suffering from a slight headache, wearing those safety goggles for hours.

A familiar flash of yellowish light could be seen in the distance, and Caitlin's step faltered for a moment as it came nearer, and in a heartbeat—with a rush of wind—the figure had passed her.

She'd seen plenty of speedsters. She'd been in the room several times when Barry had demonstrated his incredible powers. But it was always a rush to see it in person. Every time. What was it like, going that fast? There couldn't be anything like it in the world.

Funny how many people actually received those particular superpowers. The fact that it had happened more than once was anomaly upon anomaly.

She resumed walking, only to have her hair whisk irritatingly around her face as the yellow light returned.

Savitar stopped running right beside her, plodding along as if he'd gone to get lunch with her an hour ago and they were now walking to the bus stop together. He was in civilian clothes by this time, and had snatched one of the containers in her hand a second earlier.

"This isn't gonna stay warm if you walk," he informed her dryly, reaching in to pop a piece of sweet and sour chicken into his mouth.

"Parking downtown on this Earth is just as much of a pain as it is on the first one. I took the bus."

Savitar snorted and tapped the comms Bluetooth device hanging around his neck like a pair of headphones. "If you wanted food, all you had to do was call."

Caitlin faltered, glancing at him. "Are you saying you would've gotten it?"

"I eat," he reminded her, hands sliding into his pockets. After a moment of silence, he said, as if he were releasing a heavy sigh, "It's weird. Seeing you out in the city. I would've thought you'd be going crazy in the lab, trying to get back."

Back home, of course. Caitlin impatiently shoved a curl behind her ear; it kept slipping into her eyes in the wind. She had been trying not to think of the multiverse predicament, keeping herself busy with Stein and chasing down metas. Every night, before she went to sleep, she missed it—Earth-1, the place she belonged. With Cisco and Barry, Family West, the true S.T.A.R. Labs, her own bed in her own apartment. That pizza dinner at Famulari's seemed a lifetime behind her, and her whole chest ached as she lay there with the potential loss of a whole world—a whole life—she was woven into. She couldn't be stuck on Earth-66. She was part of Team Flash. She wanted her friends, her seat behind the monitors, her stupid examination table with the rust caking the back-left leg from that time Cisco had spilled lemonade all over it. Maybe she was being selfish, but it hurt to think that she might never have any of it ever again.

"What can I do from here?" she sighed, looking around at the skyscrapers in all the wrong places, cradling the food a little closer. "I know they're doing everything they can. It's being patient that's the hard part." When Savitar didn't respond, she glanced at him gingerly, clearing her throat. "What about you?"

"Me."

"What have you been up to all day?" Caitlin asked brightly, taking the sweet and sour chicken back from him. "I haven't seen you."

Savitar glanced across the street, at a nearby stoplight, at the bus stop at the bottom of the hill. "Well, since I don't really have a life outside solving everybody else's problems—"

Caitlin rolled her eyes.

"Been looking for Rory." The turn of his head this way and that, as if walking were suddenly too time consuming when there was so much to see, was very Barry. "Turns out it's hard to find people legally when you don't have a badge strapped to your chest."

Snow's eyes bounced to him, sharply. "You aren't looking for him illegally, are you?" she checked, pausing to get a better grip on the takeout bags.

Savitar reached over almost absent-mindedly and took two of them from her, carrying them gingerly, the way people hold a golf club on their first try. "No, Caitlin."

Caitlin sniffed a little. "Good."

"I guess if you want something done 'right'," he made quotation marks with his free hand in the air, all exasperation and satire, "you do it slow." He smirked. "Can't believe you ever got anything done this way."

She ignored his criticism of Team Flash's morals, for the sake of saving time avoiding an argument. "So you don't have any leads yet?" They were about two minutes from the bus stop.

Savitar shook his head. "Kinda makes you wish he'd blow something else up."

"Savitar."

"It's easier." His tone was unapologetic. Savitar stopped a few feet away when she reached their destination, handing her the takeout bags.

The screeching sound of city transportation reached their ears; they had just made it before the bus arrived. As it pulled up alongside the waiting area, Caitlin standing patiently while its passengers streamed off and into the streets, she tilted her head at Savitar.

He mimicked the gesture. "Aren't you getting on?" Nodded to the bus.

A thought had occurred to her. Maybe it was seeing him flash around in person, but suddenly the vehicle in front of her looked pretty unappealing. "I don't…suppose you could run me back?" She lowered her voice a little, smiling a bit at him. "Public buses aren't exactly my favorite way to travel."

Savitar's eyebrows shot to his hairline. "You want me to take you all the way back to S.T.A.R. Labs?" His eyes darted to the bags. "With food."

"I've seen it done before," Caitlin reminded him, a seed of smugness in her tone when she added, "Barry never spilled a drop."

She'd had plenty of practice egging Ronnie on to do things for her, taking a swing at his ego. She'd gotten him to go out of his way getting her a smoothie while they worked on the particle accelerator, to keep from forcing her onto a rollercoaster, to giving her his extra coat one December morning. She'd even coaxed him into wearing a tie once. Caitlin was not a stranger to playful manipulation, whether it was her fiancé or Cisco inviting her to one of his family get-togethers, and as it had been a pretty good day so far, she was in the mood for playing. Savitar was not the imposing villain he'd been when they had arrived; she could get away with a little teasing.

Something flickered a little in Savitar's expression at the comparison. He joined her at the bus sign, walking down until he was right in front of her. "I'm not gonna be the one carrying it," he said. Was it her imagination, or did he sound amused? He clicked his tongue, squinting at the sky for a moment. "Funny—see, I remember Barry speeding you to safety, but…I don't remember you ever doing it with food in your hands."

"What are you—"

Before she could finish, he had scooped her up and they were zooming through the city at top speed, too fast for anyone to notice they'd been on the sidewalk in the first place.

Caitlin had only experienced this once—when Ronnie and Stein had been bonded together as Firestorm, and Barry had pulled her away from the explosion meant to separate the two for good. She'd been too afraid then—afraid of losing Ronnie, afraid of not making it in time—to pay attention to what was actually happening.

It was incredible. All of Central City, all of downtown, all those details…it was like looking at a big smear on a tabletop at Jitters as they raced by. They were simultaneously apart from all of it and one with everything that was moving, superior to everything that was moving. Wind shot every strand of hair back behind her head, icy air flying all around her, and Caitlin got the feeling her cheeks would be flapping if Savitar was going the speed he normally did. But she'd tracked the speed of several metas with his abilities during the last four years, and she could tell without any kind of machinery that he was taking it easy this time around. The rate at which they were moving should have disoriented her until they came to a stop, but she could see everything with clarity as Savitar ran. She could glance down and see the food in her arms, definitely cold now, but intact as long as she kept a very tight hold on it, bags closed. She could see the cars, just for a second, at a standstill as they went past. She could see the colors on each tree. The only thing she couldn't do was hear—the sheer velocity muted just about everything.

Then there was the Speed Force. She couldn't feel it the way Savitar must be feeling it. But she saw the lightning, the faded version of the Flash's yellow electricity zapping around them with every step. It was much brighter up close, easier to distinguish, almost like the Northern Lights on a sugar high. For a moment, she was afraid she'd be electrocuted, but somehow it wasn't like actual, real lightning. It was more like a very long candle's flame, burning far away enough for her to feel warm and flicker prettily, safely out of reach. She thought if she had the strength of movement to reach out and try to catch some of it, it would scatter like dust particles in a beam of sunlight.

When they did stop, they were in the Cortex, and Savitar had set her down in the time it took to blink, standing a few feet away on the dais in the little chemical lab to the left of the main floor. He was examining she and Stein's work with hooded lids. One minute they'd been rushing through the city, and the next it was just a slow afternoon in the Cortex.

Caitlin caught her breath, trying to look composed, but her cheeks were flushed from the cold and her scarf was tangled down her back instead of her front. She set the takeout bags on the white winding desk, shifting to regain balance.

Savitar was watching her with glittering mismatched eyes. "Did I spill anything, Doctor Snow?" he asked innocently.

Caitlin smoothed her hair down, still struggling for breath, blinking probably too much. The first question that slid from her mouth was, "How is it that I am not experiencing whiplash right now?"

"If I wanted you to have whiplash," he explained, running a hand along one of the tool tables on the dais distractedly, "you would have whiplash."

"That doesn't make any sense."

He shrugged, hands fitting comfortably in his coat pocket. "Guess I'm just that good."

Savitar's smile showed his straight teeth, an exact copy of his Earth-1 counterpart's, right down to the lateral incisors. It was actually impish—nothing sinister or bitter in it; simply genuine pride and pleasure in the jog he'd just had. If this wasn't the God of Speed himself, and if she wasn't her professional-albeit-approachable self, Caitlin might have described it as adorable.

In times of trouble, Cisco Ramon always came to her with words of wisdom.

"So when I was like eight, my first substitute teacher had a handlebar mustache."

Caitlin had called Earth-1 that evening in hopes of getting an update on the breach malfunction. The line was extremely fuzzy, and she could forget about using the projector Ramon had installed in the souped-up walkie-talkie. It wouldn't even turn on.

Cisco's theory was that something was interfering with the bridge between Earth-1 and Earth-66 on a dimensional level. The fact that he couldn't vibe there—that even Gypsy, who he had specially called to their Earth for assistance, couldn't vibe there—and that mere technology was experiencing glitches, served as his proof. Not only was the matter between universes in flux, but manmade devices were being affected as well. Barry couldn't race to any universe. To be certain it wasn't just his speed, Cisco said, the Flash had insisted on attempting to break through to Kara's Earth, Harry's, and even a few they'd never tried before. To any. But nothing worked.

Distraught, Caitlin had expressed doubt that they would get a problem of this magnitude sorted out in time for Barry and Iris' wedding, let alone in the next year. Cisco had done scans and several tests to find out whether something on their end was manipulating the multiverse's energy, whether it was too many trips in between worlds, anything, but the computers simply hadn't complied. If Cisco's foolproof, futuristic technology couldn't dissect the issue, they were looking at a much longer timespan when it came to solving this.

But then Cisco had had an idea. Thus, the random handlebar mustache exclamation.

Caitlin, lying flat on her back on her bed, pulled the Bluetooth earpiece further in, irritated with the static around her friend's much-missed voice. "Cisco, what does that have to do with any of this?"

"Substitute teacher, Caitlin," Cisco had replied excitedly. She could hear him snapping his fingers, trying to get her to catch up, get on his level. "A sub. A stand-in."

"Can you be a little more specific, please?"

"Yes." He sighed. "Look, that Earth doesn't have a Cisco Ramon anymore, right?"

"Right."

"This Cisco Ramon was able to create an interdimensional extrapolator for Kara on Earth-38, right?"

"Right." Caitlin sat up, mind hurrying to fall in line with Cisco's.

"So what you need is another machine, kinda like that. And don't think I haven't tried this over here, all right? Every time I go the techno route to try to get you home, systems fail, everything fries. It's a no-go on this end. You need something that'll do this on that Earth." She heard a kind of whizzing; he was probably twirling a pencil, the way he did when he was bouncing ideas around. "Like a—a breach machine."

Caitlin raised an eyebrow. "A breach machine?"

"Not the final title. Okay? Bear with me, Caitlin. We're talking about your freedom here." It was easy to imagine him holding up a stern finger. "What I'm saying is like, a machine kinda like a doorframe, something to do what someone who vibes does. Doorframes hold doors, and Jay always told us that breaches are like doors between Earths. If you had a machine that could create and sustain a breach, regardless of whatever voodoo is keeping me from just hopping on over there and yanking you back…"

Caitlin could feel a smile forming, but it was short lived. "But…" She gripped the bedspread a little too hard, frustrated. "It's like you said, there isn't a Cisco Ramon on this Earth to build something like that. I certainly don't have any experience—"

"Aha, see!" Cisco's tone was elated. "That's where the sub comes in! You gotta get an engineer. Someone who knows what they're doing. I mean, if it can't be me, get the next best thing." Under his breath, he considered very seriously, "Hold up, that's almost too much to ask here."

Caitlin snorted. "Cisco, I can't think of anyone we could…" She trailed off, a lightbulb sparking to life in her head. She could practically see it behind her eyelids. An engineer. "Wally."

A slurping sound. It could've been anything from a slushie to a milkshake to just plain coffee in a mug. Cisco being Cisco. "Like…Wally 2.0? Wally-66?" Cisco paused. "Wally the sequel, Part 2: the Return of Kid Flash?"

Caitlin spoke over him before he could churn out more names. "Wally could do it! On this Earth he's a mechanic in training, an engineer."

"Wait, wait, Caitlin, hold on a second." Cisco must've put the drink down; the slurping was gone. "You want him to literally build a portal between two worlds. You'd have to tell him everything, okay, where you guys really come from, what you're doing here, all the nitty-gritty stuff. How do you even know he'll do it?"

"He'll do it," Caitlin promised. "You don't understand, if you—if you met him, you'd know—all he has wanted to do since we found him is help us. We just have to tell him what we need."

"Okay, so…" Cisco cleared his throat. "Say you get him to do it, right, say he's all in. He's like an engineering temp on that Earth, isn't that what you said? In training. This is gonna take serious brainpower, are we sure he can actually make something like this?"

Caitlin grinned. "He can if you teach him how."

It took a moment for that to sink in. Cisco made an extremely loud chuckle, something that sounded very much like, "Oooooohoohoohooo" and caused static to rifle through the line for a moment. When it cleared enough, he added solemnly, in his best Yoda voice, "Much to learn, you have."

It took Caitlin an hour to locate the building Wally worked in. It wasn't the biggest facility, and it was all the way on the other side of the city. Mercury Labs on Earth-66 was far less polished than the one on Earth-1, and she got the feeling by the muted interior design that it wasn't run by the same person. There was no trace of Dr. McGee in the building, and a search on her phone as she waited in the lobby for assistance told her "Tina" (as Dr. Wells had always called her) was hardly a big name in this world. The only thing that came up was records for a professor at a university in Starling City.

I wouldn't have much to say to her here anyway, Caitlin reminded herself, glancing out the window as it began to rain a little. Even if she had still worked at Mercury Labs, the two women were strangers on Earth-66.

Eventually the secretary, a stout elderly lady with very white hair beckoned her over. "How may I help you?"

"I'm here to see Wally West," Caitlin informed her, clearing her throat.

The secretary looked confused for a moment, then she brightened and said, "Oh, the new young gentleman—yes, he's up on the fourth floor today—excuse me…" She pressed the button on her headset, speaking clearly into the mic, "Doctor Allen, someone is here to see your intern? One second." She glanced at Caitlin, eyebrows pinching together. "What did you say you needed to see him for, young lady?"

"I'm—" Hesitating, Caitlin bit her lip. "I'm his doctor."

The secretary's eyes widened. "Of course, I'm sorry—" Again, into the headset. "It's Mister West's doctor, sir." She nodded, listening for a moment, then said to Caitlin, letting go of the button, "Go right up, they're in the medical lab." Then, as an afterthought while Caitlin was heading for an elevator: "Wait! You'll need clearance."

She held out a blue lanyard with a special key tag hanging from it, and Doctor Snow slipped it on, nodding her thanks.

It took Caitlin fifteen minutes more to find out precisely which room was the medical lab on the fourth floor. This version of Mercury Labs was not what she was used to. Having worked there for some time after the Singularity had taken Ronnie from her on her Earth, she liked to think she had a pretty good mental map of the place—even if working there had been a bit of a haze, moving from one task to the next, clouded by grief. But the map in her head was grossly inaccurate; everything here was either the opposite or didn't exist at all—like the chemical wing, where several scientists had tested out new theories. She could remember the slick white walls and the smell of the place. In Mercury Labs-66, it was missing.

For one thing, the doors were not marked with actual words—just letters and numbers. Things like SR05, K01, or even a simple G, all in a small frame on the wall beside the entrances. Caitlin would peek into each room, trying to work out the labels. After a few minutes of this, it wasn't difficult to come to the conclusion that the signs were initials, and one could only assume that the numbers were indicators of the amount of similar rooms Mercury Labs had to offer. Apparently, that had five rooms dedicated to surveillance—or security, same thing when there was a room filled with live monitors.

There was only one ML on the fourth floor—Medical Lab 01. Caitlin enjoyed a challenge, but in heels, mazes were never appreciated. She preferred S.T.A.R. Labs anywhere in the multiverse.

She decided against politely rapping on the door and went for the unassuming, quiet entrance. The medical lab in this facility on Earth-1 was stuffed with machinery and new medicines not yet ready to test. But the one on Earth-66 looked very much like a regular wing of your fanciest hospital: slick metal bedframes for empty cots and spotless sheets, several shelves full of different tools—the only sign that anything was high-tech was a small glass dome in one corner, housing a contraption that looked a lot like a silver washing machine.

Wally emerged from behind the glass dome, wearing jeans and a smart, pale green jacket. He was wiping his hands with a rag; they were dabbed with oil. "I think I got it," he said over his shoulder.

"Very good!"

When Henry Allen appeared a heartbeat later, Caitlin almost reached for the nearest bedframe to steady herself. His hair was a lighter silver here, and his eyes were sunken in, a lot more exhausted-looking than Earth-1's version. He wore a long white doctor's coat and a pair of what seemed to be gardening gloves. His big, relaxed smile was so similar to Barry's that Caitlin's heart skittered. How could it be fair, she wondered, that her friend's father was apart from him on every Earth? Every single one they'd encountered. Henry was either dead, a lone superhero, or missing a family in each world. A man so compassionate, so inspiring, seemed to get the worst luck no matter which life he lived.

Henry clapped a hand on Wally's shoulder, pointing to the glass dome at something Caitlin couldn't see. "Now, what you wanna do here—"

"Caitlin!" Wally had just caught sight of her, grinning away. He hurried to meet her and Caitlin offered a little wave.

Henry's smile didn't falter, widening to match his intern's. He followed Wally to the front of the room, taking off the gloves to shake her hand. "You must be Wally's doctor?"

"That's me," Caitlin replied, finding her voice after a moment of confusion. The way Mr. Allen had fixed her with those kind eyes was so familiar, her brain had stopped to stare. "I'm Doctor Caitlin Snow," she managed. He had a firm grip.

He met this with a simple "Henry" and Caitlin almost chuckled at the comparison in titles. She watched him straighten back up, letting go of her hand. On this Earth, Henry Allen had lost his wife and son on the same day. All he had left was his work—did he really do all of it with that same warmth? The warmth she remembered from the brief time they'd known each other on Earth-1, the warmth Barry still carried?

Savitar. Suddenly she saw him in the way Henry's arms swung, the way he wore the white coat with a carelessness that left the collar of it slightly askew. What would he say if he knew his father was so close, working downtown? Alive and well?

Caitlin swallowed, standing there lost in thought as Wally made up some story about her patching him up after the EXPO (conveniently leaving S.T.A.R. Labs out of it, behaving as if she'd worked at a regular hospital he'd been rushed to).

It wasn't Savitar's father. It wasn't Barry's either; even the Henry Allen of Earth-1 didn't belong to the former God of Speed. He really didn't have anyone. She blinked, attempting to imagine what that would feel like—never actually experiencing love, just the memory of it, the memory of losing it. Constantly being reminded of what you couldn't have, down to the smallest details. It was so steel-colored, so empty to think of, she shut her eyes tight with the sympathy it wrung out. She couldn't begin to comprehend a vacuum like that—but she ached when she tried, all the same.

"Well, it's about time for Wally to head on home anyway," Henry suddenly said, eyebrows raised at Wally's explanation, looking very serious. He gave the boy a stern expression. "You let me know if there's anything going on. If you need a couple days off—"

"Yeah. Yeah, of course." Wally nodded, pursing his lips, and glanced at Caitlin in a slight panic.

"Oh—no—there's nothing to worry about," Caitlin quickly informed them, pasting on a smile. "Wally should be fine, Dr. Allen, but thank you."

As Henry gave them one last crooked grin and returned to his work, Wally hurried to Caitlin's side as if rushing out of the rain, eager as a toddler.

"What's going on?" he demanded. "How'd you know where to find me?"

"I…" Caitlin wound the heels of her hands together. "S.T.A.R. Labs has some very sophisticated technology—"

"You tracked me?" Wally's arms crossed, and he looked very like Joe in that moment.

"Yes I did."

"Cool." He beamed. "So—what are you doing here, exactly?" Wally shifted, arms dropping, and his mouth opened and closed as if he couldn't quite decide which question to ask first, brown eyes dark with concern. "Is it Savitar?" He lowered his voice when Caitlin gave him deliberate, wide eyes. "Is he in trouble? Did he find out about Rory, what's—"

"No," Caitlin waved her hands, cutting him off with a wave of guilt. "It's not that. Not yet. But we are working on it," she promised. Then she bit her lip, hesitating. Was she really going to try this? Did she have any other options? If Wally was to help Savitar save the city in the future, the way she'd planning and hoping for all these months, he'd need to be shoulders-deep in the speedster's life. And this was the first step in that direction. "Actually, we—I need your help."

Just as she'd suspected, Wally's entire countenance became straighter, taller, brighter. "Anything," was the first word out of his mouth. "You got it, I am so there. Name it."

Caitlin fought a smile at his determination, focusing on the weight of what she was there to hand him. "It's about getting back home."

Wally's eyebrows dipped low; he slid his hands into his coat pocket. "What—what do you mean, do you not live here?" He pointed to the floor, obviously indicating a larger area than just that building. "Central City?" A slightly-amused smile. "Like—I can fix a car no problem, but couldn't Savitar just, you know…" He grinned. "Run you?"

"Not where I need to go," Caitlin sighed. She paused, and Wally's grin slowly slipped off his face as he watched her grow thicker and stiffer there, as he realized her situation must be a bit more serious that a malfunctioning vehicle. "Let me treat you to Jitters. It's…it's kind of a long story…."

(Author's Note: LOTS of scene changes, I apologize. Those silver thin lines must get distracting. Review, Jell-O Squares! You know they cook my rice. -Doverstar)