The security guard's death affected Barry the most, to the point that he kept seeing the man's frozen dead body whenever he closed his eyes.
Although Barry worked for the CCPD, it didn't mean he was accustomed to people dying. His mother's death had traumatized him, so when he saw that man die in front of his eyes, he felt helpless, just as he did when his mother died and his father was wrongly convicted for her murder.
What affected Barry even more was Cisco's mistrust in him. Although Cisco wasn't at fault for being cautious and deciding to keep the cold gun as a precaution against Barry, Barry wasn't in the right state of mind to listen to reason.
Felicity had a conversation with Barry and shared her own mistrust of Oliver Queen, a billionaire and former playboy. She trusted him only after seeing his vigilantism in trying to save Starling City.
Their talk did manage to calm Barry's emotions and somewhat subside his anger at himself and Cisco. But even then, he wasn't able to sleep; whenever he tried, the security guard's face would appear in his mind.
The next day, Cisco came up with a way to find Leonard Snart. "I figured out a way to track Captain Cold."
Caitlin, who was monitoring Barry's vitals and recovery speed, moved her gaze from the monitor and said, "You gotta stop naming these guys."
Harrison Wells saw through Caitlin's attempt to lighten everyone's mood, especially Barry's. Seeing her not succeeding, he looked towards Barry and said, "Barry, pay attention and listen to Cisco."
When Barry heard this, he looked around and saw everyone's mood being down. Not being able to bear this depressing atmosphere any longer, he sighed and asked, "And how will you do that?"
Cisco began his explanation, "The cold gun is powered by an engine control unit, a microcomputer that regulates the air-to-fuel ratio, so the sub-cooled fluid in the chambers doesn't overflow and..." Just as he was about to complete his sentence, Swayam, who was standing near Caitlin and Harrison Wells, finished it for him, "Explode."
"Right," said Cisco, continuing, "The ECU was receiving updates wirelessly from my tablet. If I boost the signal using Central City's network and send a false update, we'll get a ping back and then..." This time it was Harrison Wells who finished, "We can locate Snart."
When Cisco gave Barry hope that they could locate Leonard Snart, Barry only asked, "How long will it take?"
Seeing Barry ready to converse with them, Cisco sighed in relief and said, "Uh, first, I have to hack into the city's network, so I don't know, 30 minutes maybe?"
Although Cisco was a tech guy, he wasn't a hacker, so he wasn't certain how long it would take to hack into Central City's network. But then Felicity, who was a certified hacker, thought of helping. "I can do it in less than one minute. When it comes to hacking, I'm the fastest woman alive." She began typing on a nearby computer and, within a few seconds, informed them of her successful infiltration of the city's network. Either the city's network security was lacking or Felicity's hacking skills were that good, but either way, she succeeded in infiltration of the city network.
After her successful infiltration, Cisco sent the false updates and got Leonard Snart's live location. He immediately informed Barry, "We got him. He's heading west on Nelson toward the train station."
When Harrison Wells heard this, it became apparent to him that Leonard was leaving Central City, so he shared his speculations with the team, "If he's leaving, it appears Mr. Snart may have gotten what he came for."
Barry, who heard Harrison Wells' speculation, immediately donned his super suit and was about to rush towards Snart's location when he heard Cisco's voice, "When we put our minds to it, dude, nothing can stop us." Just as Cisco finished, Barry disabled his earpiece. Confused, Cisco questioned him, "You turned your earpiece off. How are we gonna talk to each other?"
Barry, still somewhat angry, told him, "I don't feel like talking right now." After saying this, he left S.T.A.R. Labs with his superspeed.
After Barry left, Caitlin began remotely monitoring his vitals, while Cisco was sadly looking at the map of Central City and observing how much distance Barry had covered. While Swayam was probing through his mind to remember anything about what might have happened in the plot during this time, Felicity suddenly extracted everyones attention and said, "You should go after Barry."
Cisco, who was downcast and dejected after what Barry said, replied, "You heard him, Felicity."
Caitlin, monitoring Barry's vitals, also spoke, "He wants to do it alone."
Felicity, who understood how Barry was feeling, looked towards Caitlin and Cisco and said, "Of course he said that. He's hurt. You're his team and friends. If I had a nickel for every time the Arrow told me to back off, I'd be as rich as Oliver Queen. Whom I mention because he's the richest person I know, or used to be."
Swayam, sitting on the side, wanted to facepalm when he heard Felicity's explanation. However, she managed to continue flawlessly, "The point is, you have your partner's back, no matter what."
Cisco, who was dejected, needed this encouragement, which lifted his mood. "I have something that might help."