~ S.T.A.R. Labs ~

Team Flash is in the Cortex after hearing the news about Ronnie Raymond.

"It appears letting Ronnie roam free is no longer an option." Dr. Wells stated.

"He's not my Ronnie anymore. He's Martin Stein walking around in Ronnie's body." Sophia reminded them.

"Is there a reason as to why Stein's brain is in control of Ronnie's body and not the other way around?" Barry asks.

"Brand new organisms will select the strongest parts of themselves to survive. In this case Ronnie's body and Stein's mind." Caitlin answers.

"So, how do we find him?" Sophia asks.

"Quinten Quail, the scientist Ronnie attacked was a former colleague of Martin Stein. And if Martin is indeed in control of Ronnie's body, he may be trying to figure out what is happening to him." Dr. Wells suspected.

~ Stein Residence ~

"Have you seen this person? The news is calling him the "Burning Man"," Barry asked her.

"Yes... I have. Who is he?" Clarissa demanded.

"He's just a person of interest in your husband's case." Dr. Wells covered smoothly.

They questioned Stein's wife a little longer, trying to figure out everything they could.

Sophia, Caitlin, and Barry followed Dr. Wells out the door and down the path.

"It seems Martin Stein and Ronnie Raymond have something in common besides sharing a body. They both need to protect the most important woman in their lives." Dr. Wells said.

"Clarissa said she feels like she's being watched," Caitlin said.

"Well, then this is the makings of a stakeout."

"Barry's meeting Iris tonight," Sophia informs her mentor.

"I'll cancel," Barry assured her immediately. Caitlin smiled at him, knowing that he was trying to be there for Sophia through all of this.

"No, go," Dr. Wells told him, waving a hand. "If we need you here, something tells me you can be here in a Flash."

~ Later ~

"Professor Stein. I'm not here to hurt you and I know you don't want to hurt anyone else so would you please not flame on." He asked, cautiously stepping closer.

Ronnie burst into a controlled flame, pushing him against the high-bricked fence. Barry fought against his hold. The screeching tires of the S.T.A.R Labs van pulled both their attention in the direction of the vehicle speeding towards them. Seeing Ronnie's angered expression, fear shot through him as he remembered Sophia.

Ronnie flew high into the sky. Barry felt his lungs tighten as the air thinned the further they soared. Barry peered down, watching as the lights of the city mirrored a clear starry night. Barry's lungs felt like they were burning with the lack of oxygen, Ronnie's hands loosened, releasing him.

"Holy crap!" Barry yelled as he plummeted. Preparing himself for the pain he knew was coming, the sudden jolt up and sharp pain of hitting metal, Barry opened his eyes to the screeching of tires behind him.

He was alive but not for long as Ronnie stalked towards him.

"NO! Don't kill him! Please" Sophia's voice cried from a distance.

After a moment passed, Ronnie exchanged a look with her and he shot back up through the sky, disappearing into the darkness.

Caitlin rushed to his side. Her hands were carefully placed over his chest.

"You okay?" she asks.

"Well, that was terrifying," Barry whispered. He winced in pain as Caitlin helped him up to his feet.

~ S.T.A.R. Labs ~

"Well, we got him," Barry said informing the team in the Cortex.

"Now what?" Barry asks.

"Professor Stein thinks that he can separate himself using Nuclear Fission," Caitlin said.

"What do you think?" Sophia asked her mentor.

"What do I think? Is it possible? Theoretically." Dr. Wells fiddled with his fingertips. "But splitting an atom and splitting a man are two very different things," Dr. Wells said.

Sophia's eyes watered when she looked up, her Ronnie was right there. Clean, haircut, in a sports jacket and jeans.

"I don't suppose it's necessary to point out that you're all staring?" Firestorm said and then all of them looked away sheepishly.

"It is remarkable. I feel clearer than I have since the accident. What did you give me?" Firestorm asked.

"A cocktail of anicycodits," Wells responded.

"Depressants and mood stabilizers," Caitlin said.

"The same formula used to treat identity disorder." Firestorm realized.

He walked towards Sophia. "I assume this was your idea." she nods shyly. "Very clever, Sophie." Firestorm smiled.

Sophia's heart broke at the nickname. He looked like Ronnie. He walked like Ronnie. But he wasn't her Ronnie.

"Don't call me that... please," she said.

"I apologize." He replied sincerely taking a step back.

"We'd like to run some tests on you if you don't mind," Caitlin spoke up.

"Of course Dr. Snow." He said.

~ Later ~

"How's Ronnie doing?" Sophia asks Caitlin.

"His temperature is running at 108.6, she replied.

"Which means Ronnie's body is rejecting steins atoms like a host rejecting a parasite. The resulting instability is causing an exothermic reaction. I worry if his temperature continues to rise it will set off a chain reaction." Dr. Wells stated seriously.

"And then what happens?" Sophia asked.

"He could go nuclear." Dr. Wells said.

~ Hours Later ~

"That's not freaky at all." Cisco walks into the room.

"It seems Ronnie's fight with the Flash has harmed the Firestorm matrix. It's unstable. Exponentially increasing the rate of fusions in his body." Dr. Wells reiterated.

"How long does he have?" Sophia asked.

"If his temperature keeps rising at this current pace. No more than a couple of hours." Caitlin stated.

"But we could fix it, right? I mean you can separate them before it's too late." Barry asked looking at Dr. Wells.

"Any attempt we make to separate the two of them could be catastrophic. A nuclear explosion... and a nuclear explosion at this magnitude would level this entire city unless the host body was no longer functional." Dr. Wells said.

"You wanna kill Ronnie" Sophia exclaimed.

"No. I don't want to kill Ronnie. But in this scenario, Ronnie is the host body." Wells defended.

"If you kill Ronnie, you kill Stein. That's two people." Cisco argued back.

"I don't know how else to stop it. And I guess that if Ronnie and Professor Stein knew the consequences we were all facing they would make the same decision. It's two lives for millions." Dr. Wells defended.

"I've already lost him once. I'm not going to lose again! You said we had a couple of hours, use them!" Sophia said and leaves the room.