Caitlin enters Barry's workplace and is fascinated to see the insides of the police station. Being a law-abiding woman all her life, she has never had to step foot inside this building.
She is surprised seeing how busy the precinct gets, officers and workers moving around, busy, trying to get their work done.
"It's so hectic," Caitlin says looking around.
"It's a busy day," Barry answers.
"Wait here, I need to submit a report to my boss before we head up," Barry says zooming away and coming back in an instant, as if he never left.
"You weren't gone even for a second," Caitlin says. "I'm glad super speed is now a thing," Barry says. Caitlin smiles and shakes her head.
"Mr. Allen, where the hell is the fiber analysis on the Orloff case?" Captain Singh asks walking towards Barry.
"Right here," Barry hands him over the report in his hand. Singh is surprised to see Barry hand him the report on time. He then turns to look at Caitlin.
"Who's this?" Captain Singh asks.
"Umm... Aaa... Girlfriend!" Barry blurts out, as it's the first thing that comes to his mind.
Caitlin's eyes widen upon hearing Barry's answer. Even Captain Singh is surprised. He looks at Caitlin, who quickly recovers and smiles back at Captain Singh.
"I didn't know you had a life, Allen," Dr. Singh says, impressed by Barry's ability to find such a beautiful girlfriend, he then smacks Barry's shoulder with the report and walks back to his office.
Once he is gone, Caitlin suddenly slaps his arm. "Girlfriend! What were you thinking?" she whispers while giving him her signature deathly stare. "I'm sorry, it's the first thing that came to my mind," Barry says.
"You couldn't have said something else? Like a personal physician?" Caitlin says as he follows Barry up the stairs of the precinct. "Well now, that you mention it, it was obvious," Barry says.
"What are you going to say to him the next time he asks about me?" Caitlin asks. "I will just tell him that we broke up, no big deal," Barry suggests.
Caitlin gives him a side eye and doesn't speak. They arrive at his lab and it's a mess.
"So this is your lab?" Caitlin says looking around.
"And that's where I got hit by that lightning," Barry says, smiling. Caitlin continues to give him her deathly stare, which makes him wipe his smile off.
"Let's... get to work," Barry suggests, seeing that Caitlin is still pretending to be mad at him. He can tell that she is not genuinely mad with his comment but he doesn't want to take chances.
They then immediately begin working on the poison sample that Barry collected from the dead bodies that morning.
Barry and Caitlin work effortlessly with each other due to their knowledge in the field.
As Caitlin is working on extracting the results of their tests, Barry can't help but stare at her. Suddenly images of a lightning storm start flashing in his mind and he sees a familiar yet not so familiar face inside the storm.
"Barry... Barry!" Caitlin calls him snapping Barry out of his trance. "Yes?" Barry questions and sits up straight in his chair.
"You were... I felt like you wanted to ask something," Caitlin says brushing her hair behind her ear. She thought Barry got lost staring at her.
"Ya, I wanted to ask something, if you don't mind answering," Barry says.
"My least favorite kind of question," Caitlin says looking at Barry, "Shoot," she says.
"... You were pretty shaken up back at S.T.A.R. Labs when Dr. Wells mentioned the Particle Accelerator. Can I know why?" Barry asks.
Caitlin looks at Barry and begins remembering the night of the particle accelerator once again.
"It's Ronnie... That night... he wasn't supposed to be there. He wasn't supposed to be there that night. He was just there for me. When the particle accelerator failed, Ronnie went down there to turn it off... manually. He trapped himself inside... to keep the explosion inside...
Sometimes... I can't help but blame myself... If he hadn't..." Caitlin says and begins tearing up.
Barry gets up from his chair and approaches her. He then brings her closer and hugs her as Caitlin rests her head on his chest.
"It's not your fault. Sometimes people need to make hard choices, and from the sound of it, Ronnie chose to save you and the people of Central City that night. In my eyes, he is a hero," Barry says consoling her as Caitlin sheds her tears.
Suddenly the computer starts beeping indicating the results are done. Caitlin moves away from Barry and wipes her tears with her fingers.
"Here," Barry says handing Caitlin the same handkerchief she gave to him a few weeks ago.
"I'm sorry for..." "It's okay, I understand how you feel. Losing someone you love is never easy. It will always be with you," Barry says, rubbing her shoulder.
"The results... they are done," Caitlin says trying to move away from the conversation.
"This says that there was no residue of gas in the tissue, poisonous or otherwise," Caitlin says reading the result.
"It must have evaporated. We'll need to get a fresh sample," Barry says.
"Wait, this can't be right. This says that there are two distinct strands of DNA inside the tissue," Caitlin says bringing up the digital reading in Barry's computer.
"How did someone else's DNA get inside the victim's lungs?" Barry asks looking at her.
"Let me try if there is a DNA match in the database," Barry says and runs the DNA found through the program, but the program couldn't find any.
"I don't understand. Why would a chemical attack leave behind another person's DNA inside the victim?" Caitlin asks when Barry suddenly has an epiphany.
Poisonous gas that can target people individually as if it has its own mind, foreign DNA found inside the victim's lungs. There can only be one possibility.
"What if this Meta-Human doesn't control gas? What if he becomes it?" Barry presents his theory to Caitlin, who too starts connecting the dots.
"All available units, we have a report of a toxic gas attack at the Central City shopping mall," Barry and Caitlin hear the police radio inside the lab turn on.
Barry immediately gets up from his chair and gets ready to run to the shopping mall.
"Barry stop, we don't know enough about what we're facing yet," Caitlin says, trying to stop him. "It's not safe!" she says sternly and grabs his hand.
"Like I said, Caitlin, sometimes people need to make choices. Everything I choose to not do something, people will get hurt. I have to go," Barry says staring sincerely into her eyes.
He then adorns his red suit at super speed and zooms out of his lab leaving a very concerned Caitlin behind.