Harrison Wells, the first one, the impostor, the killer… he had once described Barry's condition as an endless, unbroken loop. Nothing could interfere, especially a Guide. He had his heightened senses, which were under his control all the time, and on top of that there was the Speed Force. It was like another sense, sometimes more, sometimes less pronounced.

At the time he had been triggered, Barry Allen hadn't really known what had happened to him. He had been too traumatized from witnessing his mother's murder, seeing the man in the yellow suit no one believed existed, and then his father had been convicted of a crime a young Barry had been convinced he hadn't committed.

He had been ten. His mother dead, his father in jail, Barry himself in foster care, and his old life was no more. On top of that he had hypersenses. He hadn't zoned, he hadn't broken down and cried from sensory overload, and he had never told anyone about certain changes in his perception of the world in general.

Not Joe.

Not Iris.

Not his dad, when he visited him in Iron Heights throughout the years.

All five senses were heightened, though taste was the least strong one. He kept them all in check without guidance. It felt smooth and natural to him, to be able to stretch a sense, and he had taught himself to piggy-back one to the other. Sight to sound was the most prominent of these abilities. Touch to sight was a close second. Having extraordinary sight and sensitive fingers if he wanted to had helped him at work more than once.

Barry had read everything about Guides, but he couldn't imagine ever needing that kind of help with his senses, who were just fine. No Sentinel he crossed paths with ever caught a whiff of Barry Allen being a Sentinel himself. No Sentinel-Guide pair gave him more than a cursory look.

He had never stopped trying to prove that his father was innocent. It had taken him as far as Starling City and he had met someone he had believed to be a Sentinel for sure: the Arrow. As it turned out, the man was one, though with only one strong sense and two marginally heightened ones. He relied on interchangeable Guides, which was no surprise either. The guy had serious trust issues.

And Oliver Queen had never identified Barry Allen as a Sentinel. Not a single twitched eyebrow, never a second look. They had been in close proximity for a long hours, in various intense situations, and there had been nothing.

Then the accelerator accident had happened.

And he had woken up nine months later as a meta human. A meta Sentinel.

The Sentinel was equally out of the bag, at least to his team. There was no hiding that fact. Caitlin had been all over him, taking endless samples, running his genetic code again and again. They were all flabbergasted that he had no adverse reaction to running so fast, didn't trigger a zone because of what his senses had to take in or what his skin felt when he raced through the night.

Cisco and Caitlin set up more tests and couldn't get him to zone on flashing lights, strobes, loud noises, percussion and whatever else they could come up with. Barry didn't break the loop he was in. No injury, no matter how bad or how painful, set him off either. He was till in absolute control.

Joe found out eventually, shocked, surprised, but very supportive nevertheless.

"You could have told me, Barry."

"I know. I just… couldn't. I mean, it's not… I don't need help. I don't want others to think I need to be helped. I didn't even realize it until much later and…"

"I understand. I really do."

He didn't pressure him into a more active career in law enforcement and he didn't drop even so much as hint to his captain or anyone else.

When Iris discovered that Barry was The Flash he also told her about being a Sentinel. She had taken it in a stride, probably too shell-shocked to discover that he was Central City's new hero. It took her a while to work through it all, but their relationship didn't suffer from it.

No one else knew what he was, though.

No Sentinel and no Guide, and no meta, had ever caught on to what Barry Allen truly was. There had been plenty encounters throughout his career in law enforcement, and even before. No one pinged him; no one at all.

Until now.

Snart knew. Leonard Snart, Captain Cold, knew! The man had just looked at him and drawn the correct conclusions!

Barry knew Len wasn't a Sentinel or a Guide. There was nothing about any particular ability in his file. Snart would be insufferable if he was either, would have used these abilities for his heists, but he hadn't. Then again, his own status wasn't in Barry's file, so maybe it was a huge coincidence that they were both self-contained.

No, he decided. No, that wasn't it.

Snart knows, ran through Barry's mind again and again.

He had helped. And Leonard Snart understood a whole lot more about the meta Sentinel's spikes than Barry would ever have given him credit for. He had no idea how that was even possible.

Somehow, while a small part of him worried about that, he wasn't afraid. He wasn't scared of the man using that knowledge against him.

He never told the team what had really happened, just pieces of his fight with the meta whom Cisco had dubbed Scattershot. Scattershot had been picked up by ARGUS. There had been no questions as to how he had knocked the guy out and no one had remarked on the damage done to the metal extensions.

Since his suit had been fried and absolutely ruined, being out of contact had been explainable.

"I was kinda out for a while," he told them, shrugging. "Not sure how, but I made it back home and just… crashed. The suit's gone. Flakes of ash."

Cisco looked devastated. "Completely?"

"Yeah, sorry. Completely. He fried me and the rest must have… well, turned to dust when I ran home."

"Man..." Cisco groaned.

Caitlin had checked him head to toe, especially since Barry had confessed to losing consciousness, but there was no lasting damage. Cuts and bruises had healed. Possible broken bones had already set and all traces of a break had disappeared.

The whole story was the partial truth and only the partial truth. Yes, The Flash had been completely out twice, but he hadn't made it home and he surely hadn't crawled to safety on his own. He had been helped, treated and actually guarded by one Leonard Snart, and then stumbled back home after running on fumes to get some distance between them.

Because it was all too confusing to really understand.

Cold had helped him. It hadn't been the first time, but it had the first time he had patched him up.

Why?

And the more pressing question: now that Snart knew The Flash was a Sentinel, what would he do? Would he do anything at all?

Barry distracted himself with his day job. Working crime scenes. Not all were related to meta incidents, which was actually a relief, and he spent doing what he did best, outside of going really fast. He loved his job, he loved science, he loved the quiet as he waited for results and he loved the thrill of piecing tiny fragments together to find a whole new picture.

"You okay?" Joe asked as Barry walked the armed robbery scene in a jewelry store. There had been two deaths, one serious injury, and the three robbers were on the run.

"I'm fine," he told him with a brief, open smile.

"You seem a bit distracted."

Barry scribbled some notes while shaking his head. "No, I'm good."

Joe didn't look convinced. He glanced toward where patrol officers were keeping curious watchers away from the scene.

"Iris asked me to remind you about this weekend."

Barry blinked, then groaned. "The dinner…!"

"Yes, the dinner. Don't forget about it. Don't be late."

Barry grimaced. "I won't."

The look on his foster father's face was tell-tale. "In case you haven't checked your calendar: tomorrow is Saturday."

"And dinner is… Saturday?" he hedged a guess.

Joe gave him an exasperated look.

"Saturday. Right. Tomorrow. Got it," Barry said quickly, shooting the older man a smile. "I'll be there."

He was. Right on time and looking only a little windblown.

The dinner helped to distract him a little from everything that was going on inside his mind. There were so many conflicting emotions racing through him that Barry was getting whiplash.

He managed to forget it all for the evening hours he spent having a lot of really good food, wine that didn't do a thing to him, and then dessert that shouldn't even be possible to stomach by a normal human being.

Eddie gave him an almost jealous look. "One more bite and I think I'm going to burst," the man groaned.

Joe patted his own stomach. "I'm going to regret this so much, but it was wonderful, baby."

Iris chuckled and pushed another cup of chocolate mousse at Barry, who rolled his eyes. But he ate it.

"You're the nightmare of every dietician," Eddie griped.

"And he'll be hungry again in a few hours," Joe teased.

There was a beep from Barry's cell and he glanced at the screen.

"Or sooner," Eddie corrected, more serious now as he took in Barry's expression. "Business?"

"I… gotta go," Barry said, shooting them an apologetic look.

Joe nodded. "Be careful."

He shot them a wide smile. "Always am." And he raced off.

Barry had expected to at least get some taunts from Snart. Maybe a text. Maybe even a late night visit with some brief exchanges and at least one hidden threat.

There was nothing.

Barry didn't want to look into his feeling of worry all too deeply. He pushed it away, was his usual self with everyone, be it at his paid job or his unpaid freelance one. On the inside, he was rattling around like a bowling ball in a steel cage.

The Flash tried to avoid Cold for a while. Barry Allen was doing the same when it came to Leonard Snart.

It wasn't really a problem since the man was laying low. Really low. There were no heists, not even a simple theft, and while Barry suspected that Snart was behind a small burglary, he didn't really see him or even any evidence that it had been him. Barry had been the forensics tech on the scene, but the trace evidence had been scarce. And such a small time job didn't really scream 'Leonard Snart'.

So what if he scoured the more recent case files to maybe catch on to what Snart was currently doing in Central City? Nothing caught his eye. There had been no thefts, no hold-ups, no suddenly missing precious stones, art work or antiques.

If not for the fact that the man had dragged his bleeding, broken form into his hide-out, Barry wouldn't even have known Snart was in town.

Two weeks after their encounter, The Flash finally caught the tail end of a fight that involved ice from a cold gun, and he almost whooped in delight. And something like relief flooded him.

Snart looked at him, eyes hidden behind the specialized glasses. For a long second they stared at one another while sirens blared in the distance and some low-life criminals groaned on the ground. Everything was covered by a thick sheet of ice, including the getaway car, and a meta was unconscious inside the hunk of ice. The meta who had instigated the whole break.

"What?" Barry managed.

"No one poaches on my territory." Cold saluted lazily, then holstered the weapon. "Especially noob amateurs. Really gives us… professionals a bad rep. You're welcome…. Flash." He smirked and disappeared down an alley, each step measured as if he dared The Flash to stop him.

Cisco's voice sounded distantly in is ear and Barry answered almost distractedly.

Something inside of him reacted strongly, felt something… something that seemed incredibly compatible, which was alarming all by itself. His eyes were still trained on the alley and he really wanted to run after Cold, but he had a job to do first. The meta needed to be handled.