Kara was worried. All day long, Barry had been seeming to exhibit precognition, knowing how conversations and events would unfold before they actually happened. This ability had come out of nowhere, and she was concerned that perhaps it may have been a side effect of his super speed that they hadn't yet considered. Not knowing what else to do, she headed to STAR Labs and brought up her concerns to Wells, knowing one thing for certain- that if anyone would know how to handle this, it was him.

"I'm worried about Barry," she told him. "Today, all of a sudden, it's like he has precognition. He seems to know how certain things will happen before they actually do."

"And this worries you because?" Wells asked.

"I'm just wondering if maybe it's a side effect of his super speed that we hadn't considered," Kara replied. "And I'm concerned about what effects it might have in the long run."

"All right," Wells said, nodding. "Well, let me talk to Barry and see if I can't manage to puzzle out a bit more about the phenomenon you've described. Sound good?"

"Yes," Kara replied. "Thank you."

"Of course," Wells replied in an oddly distant tone of voice, and wheeled himself steadily away, out of Kara's sight.

Later, completely by accident, she overheard Wells and Barry talking.

"You ruptured the timeline, didn't you?" Wells was saying when Kara came into earshot, which, for her, was still quite a long way off. "You're experiencing temporal reversion."

"Yeah," she heard Barry reply, sounding relieved to at last have a term for what he was going through.

"How long?" Wells asked.

"A day and some change," Barry answered. "It's like I'm living it all over again.

"Yes, well, that's good," Wells said. "That means there's not too much you could have messed up yet. How did this happen?"

"I- I don't know," Barry stammered. "I mean, I was running faster than I ever have, and the first time that I lived this day, some really horrible things happened. There was a tidal wave, and-"

"No," Wells interjected. "Do not tell me. I do not want to know anything about the future you experienced. Nothing!"

"Okay, but Doctor Wells, I-" Barry began.

"Barry," Wells cut in. "Time is an extremely fragile construct. Any deviation, no matter how small, could result in a cataclysm. Now, here's what you're going to do- everything you did before. Every word you uttered, every step you took, you're going to do it again, and you're not going to tell anyone that this happened."

"Okay," Barry replied, though he didn't sound particularly enthused by the prospect, and as far as Kara knew that was the end of it. She was relieved to have an explanation for Barry's apparent precognition- whether she'd been meant to hear that explanation or not- but aside from that her worry continued unabated. She knew that it wasn't very likely that Barry would actually do what Wells had told him and not do anything to change the course of this day. It was obvious that some terrible event was looming on the horizon, and that Barry thought that he could stop it. There was no way that he could be convinced not to try, and Kara worried that he was going to get hurt.

A few hours later, Barry walked into STAR Labs with Mark Mardon in tow. Kara, like the rest of the team, knew that he had been the one who had murdered the coroner, but she hadn't expected Barry to bring him in quite so quickly. At least he hadn't gotten hurt the way she'd feared he would, but, as he proceeded to lock Mardon up in his own specialized cell in the pipeline, Kara could see that she had been right about there being little chance of Barry doing what he'd been told, as Wells was cross with him in a way that suggested that by going out and capturing Mardon, he'd ignored his express command that he not do anything to alter the timeline.

They didn't have time to confront the problem, because shortly after Barry showed up at STAR Labs with Mardon, Cisco disappeared under odd and suspicious circumstances, and they soon learned that Leonard Snart had taken him hostage, which unfortunately tracked with what Joe had told Barry about him being back in town. When Cisco was finally released and made it back to STAR Labs, he told them, while obviously filled with guilt and regret over the entire situation, that Snart had forced him to rebuild his cold gun and Rory's heat gun, along with creating a weapon for his sister to wield, as well as reveal the identities of the Flash and Supergirl. At this news, Kara had a moment of silent communication with her brother. This would be the third time they had faced off against Snart, and normally they wouldn't be worried about the probable outcome, but the fact that he now knew their identities complicated things. It put them, their loved ones, and anyone they associated with on a regular basis at risk. Nevertheless, Kara could see that they both knew that they had to do something. Snart couldn't be allowed to break the law indiscriminately just because he possessed knowledge that could be used to hurt them. With that decided, they knew that the only thing they could do now was analyze what Snart had been doing since he had returned to Central City to figure out what his next move was and then stop him before he could make it.

"The casino wasn't the target," Barry told them a short time later, after their requisite digging into Snart's activities since his return had uncovered the information.

"Then why did he do it?" Cisco asked.

"Casinos keep tons of cash on hand to cover their markers, not to mention the money that they make," Kara answered, remembering the information from when she'd done a piece on said establishments.

"But when they're under attack, the protocol is to relocate the money outside of the casino," Barry added.

"So, that was Snart's plan all along," Wells concluded. "To trigger the move."

"Okay," Cisco said, speaking for all of them. "Where is it now?"

It wasn't long before they found the answer, and Kara found herself following after Barry as he snatched Snart and sped him away from the would-be scene of the crime.

"Good to see you, Barry," Snart taunted when they came to a stop in the woods, outside city limits. "You too, Kara."

"We have to talk," they both told him in unison. Barry pulled down his cowl and added, "I know Cisco told you who we are."

"Can't really blame the kid for giving you up," Snart said noncomitally. "You or his brother? Come on, I put him in a tight spot, the same kind I've got you in right now." Kara wanted to say something in response, but she sensed that they should let Snart speak his piece, and for the moment Barry seemed to be speaking for both himself and her anyway.

"You can't really stop me not that I know who you are," Snart went on.

"I could speed you to my private prison where you'll never see the light of day," Barry said. Kara couldn't resist throwing a shocked glance in his direction at those words. The pipeline was meant for metahumans- which Snart was not- and even then only because there was nowhere else they could be kept where they wouldn't be a danger to anyone else. It wasn't meant to function like the ARGUS prison on Lian Yu.

"You could, but then I wouldn't be around to stop my own private uplink that'll broadcast you and your sister's identities to the world," Snart replied smoothly, unperturbed. "So, the million dollar question- what to do with me now, Barry Allen?"

"I won't let you keep stealing whatever you want whenever you want," Barry said. "It has to end."

"Can't do that," Snart replied, tilting his head slightly in the barest gesture of his disagreement. "It's what I do."

"Then find a new line of work," Kara put in, finally finding an opportunity to speak.

"Don't want to," Snart replied, turning to her.

"Why is that?" Kara asked, her curiousity piqued.

"The same reason you two keep running after guys like me," Snart said. "The adrenaline. The thrill of the chase. I love this game, and I'm very good at it."

"Then go play it somewhere else," Barry interjected. "Leave Central City."

"Can't do that either," Snart replied. "I love it here." He inhaled deeply and added, "This city is my home." Barry scoffed.

"You've seen what we can do," he said, gesturing between himself and Kara. "You know

that we can stop you. If you want to keep pushing your luck, go for it, but from now on no one else dies."

"If you're as good as you say you are, you don't need to kill anyone to get what you want," Kara put in.

"That's true," Snart conceded.

"And if you or anyone in your rogue's gallery goes near any of our friends or family again, we don't care who you tell our identity to," Barry went on. "We're putting you away."

"I guess your secret's safe," Snart replied. "For now."

"Oh, I don't suppose you'd give me a ride back to town, would you?" he asked after a moment. Barry just smirked at him and raced off, leaving Kara to follow after him.

Later, as they headed into Jitters for a celebratory coffee, they ran into Caitlin, Iris, and Eddie. The latter, upon spotting them, ran up to Barry and enveloped him in a hug.

"I'm so sorry, pal," he said, pulling back. "It's not like me to hit anyone. I don't know what came over me."

"Uh… thanks Eddie," Barry replied, looking bewildered, and Kara had to wonder exactly when and for what reason Eddie had hit him. "It's- it's okay."

"You poor thing," Iris put in, laying her hand on Barry's shoulder. "I had no idea."

"Is that right?" Barry asked, still confused. "Um, what exactly did you have no idea about?"

"I was just explaining to Iris and Eddie about your lightning psychosis," Caitlin said, giving Barry a pointed look.

"My what now?" Barry asked.

"Your lightning psychosis," Caitlin repeated. "How your recent odd behavior is a side effect of being struck by lighting: mood swings, sudden outbursts of affection, and other… lapses in judgement."

"He has had all of those things," Iris supplied. "He told me he had ESP."

"Yes, it's a very uncommon neurological phenomenon," Caitlin replied. "We're only just starting to research it in keuranomedicine. It's why Barry's been spending so much time at STAR Labs."

"I just wish you would have told me," Iris told Barry softly.

"It hardly feels real sometimes," Barry replied.

"We're just happy you're getting help," Eddie put in.

"Yeah," Iris agreed.

"So… we're good?" Barry asked.

"Yeah, we're good," Iris confirmed. Barry nodded, looking relieved, and Kara took the opportunity to pull him away to get the coffee they'd come in for the first place.

"What did you do?" she asked as they made their way to the counter. Barry shook his head but otherwise didn't answer her.

"Seriously Bar, what happened?" Kara persisted. "What did you do that was so bad that Caitlin literally had to make up a neurological disorder to cover for you?"

"I don't want to talk about it," Barry grumbled as they waited for their coffee, and then clammed up, evidently determined to hold to his statement of not wanting to talk about whatever it was that had happened. Despite that, Kara's curiosity had gotten the better of her and she continued to badger Barry about it the whole way home in the way only a younger sibling could, laughing depsite herself at her brother's stubborn refusal to give in.