Rendering a room or even a whole building happened more easily now. It was also a lot more complex. It was a reality inside his head. It was there, but not physical. The ability was something that had never been an effort, but now it was almost extremely easy. Make the plan, execute the plan, adapt the plan on the run and with ease, without prior planning of Plans B to Z. It fell into place around him.

With Barry, adaptation was a given. Regularly. Actually, almost always.

Snart had verbally ripped him a new one over rushing in without a plan long before the current status of their partnership, and he had finally gotten the younger man to at least listen to a plan and weigh all the options.

Len's perception of a given space, any space, even one he hadn't cased beforehand, was rapidly growing. He could walk into a building and his brain started to click the puzzle pieces together within seconds, creating the layout and leaving him with blueprints that were growing with every corner he took. His mind was moving at the speed of a speedster, computing on a level that stunned Caitlin and had Cisco theorizing about cross-contamination of the Speed Force.

Which wasn't possible.

"I agree," Harrison said slowly. "You can't 'catch' speed. You can't become a speedster or a partial speedster through proximity. Barry's not patient zero of a spreading disease."

Barry grimaced.

Len's expression was flat and unreadable. Yes, it sometimes felt as if he tapped into the Speed Force, his mind racing along a path he had used before, but never this efficiently. Leonard Snart wasn't a meta, just had some undocumented abilities, unknown on this Earth, that were a mixture of Sentinel and Guide to a degree. His mind had always worked different angles at a fast pace, rendering a room, but now it happened without effort.

"It seems that Mr. Allen's… meta Sentinel has had an effect on you," Wells mused with a smile. "It challenged your mind to use the already present potential at an exponential rate, and the curve rose steeply. Tell me, how long did it take you to render the last building you walked into?"

"Two point nine seconds."

Cisco gaped. Barry shot him a look that was a mix of pride and surprise.

"In detail?"

Len shrugged with one shoulder. "Five point seven."

"Holy moly…" Cisco breathed.

"It's a knack," he drawled lazily. "I got better."

"They are not bonded," Caitlin objected. "They can't be! Barry can't bond!"

Harrison shrugged. "Your world might not have heard of conduits, shields and anchors, but mine has never heard of all three abilities manifesting in one person." He nodded at Len. "Nor do we have metas. Maybe there is a dimension out there where self-contained Sentinels are connected to specialized Guides like Mr. Snart and it's absolutely normal. And can be explained. So far, we only know what your science and the little I can fall back upon tell us."

"You say it's possible that a self-contained Sentinel can bond?" Caitlin wanted to know, arms crossed in front of her chest.

"There is a whole multiverse out there, Caitlin," he answered calmly. "Somewhere someone like Barry and Len are bonded, possibly with an empathic component, maybe even a life-bond, and it's not questioned. There are a thousand possibilities with another thousand variables. We cannot understand their connection with our science, but the evidence is here." He looked at Len, then his eyes travelled to Barry. "When a Sentinel finds their Guide, both parties grow. Their abilities are balanced in each other, challenging the other on all levels. We noticed how Barry's control of his powers has grown, how he became faster, more adaptable, discovered new abilities at an exponential rate. You, Leonard, have grown, too. Your own latent rendering is now stronger, clearer. You always had a connection to time, whether you were aware of it or not. Apparently you just needed… Time… to develop it all."

Len's whole body had stiffened and he shot the other man a warning scowl.

Wells looked unimpressed.

"You're not going to stick needles in me," Snart stated, voice flat, eyes emotionless. "I'm not participating in any of your little tests."

Caitlin opened her mouth to protest, but he cut her off with a raised hand and a sharp look.

"I'm not your guinea pig, Dr. Snow. I'm not going to run through mazes, solve riddles or earn brownie points of any kind." He looked at Harrison. "Does this endanger or hurt Barry?"

"What?" the speedster in question blurted. "No! I don't even… there is nothing!... I can't feel a thing!"

"Apparently not," Wells added wryly, shooting a smirk Barry's way.

"As long as there are no drawbacks," Snart said coldly," I'm not playing."

"We don't know if there is anything going back and forth unless we look for it!" Caitlin told him. "And test for it!"

Len's expression was icy. "No." A warning swung in that one word and it was a warning that should be heeded.

She glared at him with a similar expression.

"Cute," he only commented.

Then he walked out of the cortex. Barry was at his side within the blink of an eye.

"Don't," Len grated.

"I wasn't going to."

"Good."

Snart stopped at the bike and grabbed the helmet. He looked at his speedster, saw the green eyes filled with understanding and much deeper emotions. Nothing was said and Len jammed the helmet onto his head. He straddled the bike, gunned the bike and drove off, weaving through the afternoon traffic.

The Flash didn't follow.

He took the long, very scenic route to one of his rarely frequented safehouses.

Barry walked into the house in the early hours of the morning, just past three a.m., a day later. He was carrying a stack of food boxes from various restaurants. Len looked up from where he had been tinkering with one of his guns, smirking.

Snart himself had been working this late, or early, depending on the point of view, for different reasons. His plan had been to call it a night soon, which had now coincided with the arrival of a certain speedster.

"Eclectic," he commented as Mexican, Chinese, Japanese, Italian, German and plain old American style burgers appeared like a buffet on the cleared work bench.

Barry opened the Chinese take-out box and attacked the food with gusto.

"Is any of that for me or just your appetizer?" Len drawled, walking over to his speedster. "You are a bottomless black hole, Barry Allen."

"What can I say? Patrolling makes me hungry."

"Slow night?" Len picked up a box of fries and dipped them in salsa.

"Yeah. Just a few burglaries and one unlucky guy trying to break into a car."

He hummed.

Barry reached for some nachos and Len watched him clear them within minutes. He saved a burger for himself before the speedster could eat that, too. With his prize he went back to his tinkering, while Barry stretched out on the couch as he had done so often before, relaxed, at ease, and metabolizing food that would have fed a small village in a third world country.

It was so normal.

Snart smiled to himself, his own form relaxing, enjoying Barry's presence as he kept on working on his little project. The tension from the slightly more heated than normal argument with Caitlin had come and gone, but there was still a knot sitting deep inside, one that refused to unravel.

"Cisco will have a conniption if you keep tinkering with his guns."

"My guns," he said slowly.

"Well, he built them."

"And gave them to me. His bad."

Barry cracked an eye open, craning his neck to look at him over the edge of the couch. "Huh. Right. He should have learned."

"Precisely." He clicked the last piece into place, then regarded the streamlined weapon with a faint, appreciative smile.

Barry stretched and Len was momentarily distracted, then the smile of appreciation grew.

"Bored?"

"Nope. Actually, I feel absolutely relaxed." He grinned, all mellow and warm, radiating a deeply rooted contentment.

"Addict."

"Hm, maybe."

"Sucker."

"Definitely." Barry yawned and closed his eyes.

"I have a perfectly good bed, Scarlet."

A green eye cracked open. "Is that an invitation."

"To sleep," he deadpanned.

The smile was soft and private. It tugged at the knot, pulling it apart, made Len breathe a little easier.

When had he started to get this invested, this close to people, this… involved? Barry, yes. He had always cared about the speedster. The emotional ties were there and wouldn't go away, he had realized a long time ago. And they were only getting stronger.

The rest of the team had never mattered. He had never cared if he hurt anyone's feelings with his actions or words, and he had never felt anything they had said hit home.

Now it had.

Barry rose and walked over to him, pulling the unresisting man into a kiss. Len went with it, let himself be drawn in and urged toward the bedroom.

Nothing happened, aside from kissing Barry, which he enjoyed a lot, and running his hands over the warm, lean form, which he enjoyed just as much. His partner fell asleep, giving in to the need for that much-needed rest before tackling the world of forensic science in a few hours.

Len watched him for a while; a long while. And he was still smiling to himself.

It was easy. So very easy. As it had always been. It was a flashback to how this had started, how it was between them, and what he wanted.

"You're so bad for me, Scarlet," he murmured. "So very, very bad. And I like bad. I adore bad. I want bad."

Barry was wide awake and ready to get to work three hours later, thanks to his speedster metabolism and the need of so much less sleep. Len held out a large mug of coffee as his Sentinel ran all ten fingers through his hair, trying to tame it, actually making it worse. He would catch up on sleep later.

"Thanks." Barry gave him that bright smile and a kiss that tasted of the mint toothpaste Len kept in the tiny bathroom. "Want to tag along tonight?"

"Pass."

"Got plans."

He gave him a smirk. "Possibly."

"Plans that involve The Flash?"

The smirk grew.

Barry chuckled and drank his coffee.

"Have fun being a good guy," Len told him.

"I know you'll have fun doing whatever it is you're doing," came the teasing reply. "Don't get caught."

"I feel insulted," he deadpanned.

It got him a brief kiss, then Barry was off to work. Snart leaned back, smiling to himself. It was a smile quite unlike him; warm, affectionate, loving.

Two weeks after his talk with Joe, Barry stopped short as he walked into the cortex. In one of the adjacent labs, separated from the main control room by clear walls that mimicked windows, Joe was talking to Harrison Wells. Both men were deep into their conversation and Wells was showing something to the detective, gesturing, smiling, nodding, and Joe apparently kept asking questions.

"Uh, hey, Caitlin," Barry greeted their resident doctor and geneticist with an almost distracted air. He waved a hand at the lab. "What's Joe doing here? New case?"

Because if it was, how come he hadn't heard anything about it? His own cases at his daytime job were rather clear-cut and meta-free. Attempted robbery, one theft, and two murders. He was processing normal evidence and that was… nice for a change.

"Oh, no new case," Caitlin answered, glancing toward the two men. "Joe had some questions."

"About?" he prompted.

"You and Snart." She gave him a sympathetic smile. "About how this whole complicated not-bond works."

"What?!" he blurted. "Why?!"

"He wants to understand, Barry. Same as all of us."

"He could have asked me!"

"And what would you tell him? That Snart just feels right? That he helped you decompress?" She raised an eyebrow.

Barry nodded.

"It's a purely personal feeling, Barry."

"Well, it is a purely personal relationship!" he almost snapped.

Caitlin raised her eyebrows and he scrubbed a hand over his neck.

"The people in your life have been confronted with Leonard Snart before. Multiple times. A man who had a rap sheet for a reason. A man who served time and was absolutely guilty of all the crimes he was accused of. Joe can't just look at it from your angle."

His features hardened and he felt a surge of anger. "The criminal angle."

Caitlin's face was pure sympathy now. "Isn't that normal? He's not a Guide, Barry. You're not a normal Sentinel. You're in an endless loop, all your senses balanced. There is no connection between you," she raised her hand as he started to interrupt, "that we understand. What Joe tries to understand is what the two of you really are. How something that has never occurred on this Earth before can be as solid and real as a normal bond."

Barry groaned and interlaced his hands behind his neck. "It's real! Why can't anyone trust me in this? I can feel it!"

"Barry… Give your father time. And see it from his point of view. He knows the criminal record, he has seen what Snart has done, and now he's suddenly your shield? It needs time. He is your father. He is worried about you. He wants what's best for you, correct?"

He knew that. He understood it on some level, but Barry felt like they were treating him like a fragile thing, threatened by the big bad supervillain. Len was the same man he had first met as Leonard Snart and who had later become Captain Cold. Yes, he was a criminal. Yes, Barry wouldn't be able to change him. No, he didn't want to. But Len's instincts had shifted to something new after their first encounter and that had only ever gotten stronger.

Barry felt him within the Speed Force. He felt how the Speed Force reached for the other man, surrounded him – loved him. The control Len gave him had pushed his abilities so much further, had made him faster, had given him a new edge, especially coupled with his senses, and those senses also told him that this was good. Perfect.

"Mr. Allen."

He looked over to the lab, found Wells and Joe watching him.

"Barry," the detective said with a smile.

"You could have told me," he simply said.

Joe smiled ruefully. "I could have. I just wanted to get the sciencey explanation on this thing between you and Snart."

"Sciencey?" he echoed with a laugh.

Joe smirked. "I know you can talk science all day, kid, but this was something I wanted a third party's opinion on. Someone to explain it without emotions involved."

Barry nodded. "Okay. Alright. So… it's okay?"

"I need some time to adjust to the idea of the two of you, but yes, it is okay and always will be, Barry."

"But still no Christmas dinner?" he joked.

Joe grimaced.

Barry walked over to him and gave his foster father a hug. "It's okay. Len's not much of a holiday person."

"Uh-huh."

"Thanks for trying to understand, Joe."

West squeezed him tightly. "Always. I wrapped my head around you being a self-contained Sentinel, then The Flash, and finally the meta Sentinel. I can do this, too."

"You're a pro," Barry teased.

He chuckled.

"How disappointing," Len drawled as Barry told him that Christmas dinners or any and all other holiday invitations were most likely never going to happen. Let alone other occasions. "I was looking forward to that tense, ready to cut with a knife air, possibly a gun on the table." He grinned sharply. "Maybe even a threat or two before the main course."

Barry bumped their shoulders together. They sat on the couch in his loft, watching a movie, eating popcorn. In Barry's case, the large tub was all for himself.

"Iris offered," he told him.

"Charmed. But I have to decline."

"She just wants to get to know my better half. Her words, not mine," he laughed at Len's disapproving scowl.

"I don't do family dinners, holidays or birthdays." There was a warning in that. "Any of that."

Barry leaned fully against him. "That's okay." He ate more popcorn, clearly enjoying their movie night.

Len managed to steal a little of that delicious treat. He was a thief after all.

Tasting the salt and butter on Barry's lips was like a dessert.

While he didn't do holidays and birthdays, he did do coffee dates. At CC Jitters. With Iris West-Thawne.

When the email had come in through one of his many dummy accounts, he had been mystified. Barry had simply shrugged and told him that Iris had asked for an email where to reach Snart, so that solved that riddle. That it was an invite for coffee, getting to know her brother's partner and not-Guide, had been more of a surprise than a mystery.

Curious, Len had accepted.

So, all senses on alert, eyes scanning the crowd, rendering the café's main floor in seconds, he walked into the coffee shop. It had never been on his list of possible targets, mainly because aside from really good coffee, Jitters had nothing of interest on offer; at least for a master thief.

Iris had already been there, sitting at a corner table that got his approval because of the strategic location, and her smile had been warm and welcoming. If not for the fact that they weren't related by blood, Len would have called it Barry's smile. Well, they had grown up together, even before West had fostered Barry Allen, so they were a lot like siblings.

"Mrs. West-Thawne," he greeted her with polite distance.

"Iris," she told him.

Len inclined his head. "Iris it is. Do what do I owe the pleasure?"

"I just want to get to know you better. The one person in Barry's life who had such an impact on him."

His face remained carefully bland. "For better or worse?" he teased.

She chuckled. "Maybe. Barry was always bad at flirting, so what the two of you have? Had? Well, it does fit his track record."

Len found himself snorting with amusement.

"So yes, I'm happy to finally meet you."

"You really need to do your homework," he drawled. "Then you might take back some of that statement."

She sipped her coffee, sharp eyes on Len. "Oh, I wouldn't. I've known Barry for almost all his life. Not just as my foster brother, but also before. And I know when he's head over heels for someone, which hasn't happened a lot since, you know…"

"Quite."

Iris held Len's gaze. "I know who and what you are, Leonard Snart. That doesn't refer to your past, though. I'm only interested in the present."

"Alright," he replied with nonchalance.

"And while I would have preferred to meet my brother's not-Guide at my home, preferably over a nice family dinner, I understand there are certain… reservations."

"Like your father threatening to shoot me?" Len raised his eyebrows.

Iris grimaced. "Well, yes, that."

"Don't worry, I'm rather good at not getting shot, especially by the police."

"I really do hope so. I know it's not the same, but you are kind of like a brother-in-law," she told him with a wink throughout the first meeting. "I think Barry prefers you not getting shot."

His eyebrows shot up.

"This is… real, correct?" she added. "It's not a fling. It definitely isn't a one-night stand. You're way past that."

"Correct."

"It's long-term. Forever."

Len felt himself tense. Her smile was almost disarming, absolutely honest and without pretense.

"Barry loves you. A lot. I can see it in the way he behaves, how he talks about this, between you. This isn't a fling for him either, or just infatuation."

"Is this your way of a shovel talk? If it is, kudos. Preferable to the way your father handled it."

She grinned. "He can be a bit much."

He gave her a humorless smirk.

"It's not a 'hurt my brother and I'll kick your ass' talk. You won't hurt him."

"Do tell."

"You are his partner," she simply stated. "His shield." Iris picked at her muffin. "How open are you to dinner at my house sometime? Without my dad."

Len blinked at the sudden change of topic. "Not at all. Your loving hubby is also a cop. I think you can do the math."

"Eddie knows about Barry, about you, about this between you. He knew before my dad and he was the one to kick Barry into talking with my father about it."

"Still decline, thank you. I'm not the dinner kind."

"Alright, so it's twenty questions at CC Jitters," she told him with the bright smile.

That was how the coffee dates were born.

And Len enjoyed himself.

Iris was a likeable person, very protective of her brother, warm, loving, and also curious. She had a sharp mind that connected dots others hadn't even seen and she understood that what was between Len and Barry was not something anyone could really explain.

So yes, he came to their little coffee dates. That Iris was sometimes picked up by her husband was quite entertaining, too. The first time Eddie Thawne had walked into CC Jitters he had almost done a double-take, clearly surprised to find his wife having coffee with Leonard Snart.

"Detective," Len drawled, smiling.

"Uhm," Eddie glanced at his wife for clues. "Iris?"

"Oh relax, Eddie. It's a coffee date."

"Date?"

For a police detective he was looking like he had just been completely overrun by the facts presented to him.

"Don't worry, detective," Len told him in a lazy drawl. "I'm already spoken for."

The blond opened his mouth, then shut it again.

"Eddie," Iris sighed. "Sit. Have some herbal tea. Len and I are just talking."

"About?" He shot the other man a sharp look

Her scowl was almost fierce.

Len really liked her. He hid the smile behind his coffee and gave Thawne an innocent look. The detective looked resigned and just sat down next to his wife. Len rewarded him with a trademark smirk.

"Nice of you to join us," he deadpanned.

"Play nice, boys. Len's part of this family now, Eddie. No matter his… official status," she added when her husband looked like he wanted to argue.

Thawne raised both hands. "Whoa. Not saying anything."

"Good."

It was the start of getting to know the couple, Barry's sister and brother-in-law, the latter making himself mostly scarce when Iris and Len had their little dates.