While the team gets busy building a trap for the man in Yellow, Barry decides to look into Ronnie because a dangerous meta-human like Ronnie shouldn't be left out in the open.
Luckily, Barry literally works in the CCPD and has access to criminal files. When Barry looks into Ronnie's files, he sees that Ronnie is a career criminal.
Started robbing small stores at the age of fourteen, then went on to become a con man, conning people out of their money by manipulating them, then went on to become a bank robber. Robbed a few banks successfully before disappearing and lying low for a while.
The next time he did appear was literally when he saw Caitlin and started stalking her.
Used his con man skills to get closer to her and made her fall in love with him.
Barry realized just how different Ronnie is compared to the one he saw in the TV show, but there was also the evil version of Ronnie from a different Earth.
A change in the past is all it took for a man to go from being normal to a career criminal.
Barry informed Joe about Ronnie and how he is a danger not only to Caitlin but to the city. His past actions and his present powers are a threat to the city.
Joe understands this and makes sure that Captain Singh is informed about this Meta Human, and the Meta Human task force that Eddie leads, is already on the case.
Barry joins Eddie as they go to all of Ronnie's past hangout spots and ask around if anyone has seen him recently. But they have no luck in this regard.
Having no success at CCPD, Barry returns to S.T.A.R. Lab and uses all the city cameras they have access to run facial recognition on Ronnie.
"What are you looking at?" He suddenly hears Caitlin's voice behind him. Barry turns around and sees Caitlin looking at the screen curiously.
"Ugggg, I was trying to see if any of the cameras picked up Ronnie," Barry says.
"Let me help you with that," Caitlin says and sits down next to him.
"Are you sure?" Barry asks worried because of her past with this man.
"Don't worry. I will be fine, plus I also want this asshole caught as soon as possible, so he doesn't bother me ever again," Caitlin says.
"You seem fired up," Barry says, smiling.
"After what he tried to pull off yesterday, I am going to make sure he regrets ever coming after me," Caitlin says, sounding a little scary.
Looks like having Barry in her corner has made her much more confident, and she should be. To this day, Barry has never faced anything that he couldn't take care of.
Caitlin has seen at extent what Barry can do, so having someone so powerful beside her is a huge confidence boost.
Caitlin joins Barry as they start skimming through all possible sightings until Caitlin finally finds something.
"Found him!" Caitlin says, grabbing Barry's attention. Barry rolls in closer to look at her screen as he sees footage captured by one of the street cameras. In it, he sees Ronnie entering a sewer after looking around cautiously.
Barry frowns.
'A sewer, again? I really need to see what's going on down there,' Barry thinks.
"Did he come out afterward?" Barry asks.
Caitlin quickly pulls up every camera footage they have, looking over a manhole across the city. They spend an hour going through all the footage while being assisted by the AI and facial recognition.
There is no sign of Ronnie anywhere.
"I will be right back," Barry says, getting up from his chair.
"Where are you going?" Caitlin asks.
"Into the sewers," Barry answers.
"Now?" Caitlin asks, surprised. "Yes, I feel like something is going on down there. First it was Woodward, now Ronnie. Metas go in and disappear, never to appear again," Barry says, and in a flash, puts on his suit and runs out of S.T.A.R. Labs.
With his incredible speed, Barry immediately reaches the closest manhole and goes in fast. He doesn't want to smell the shit and running at super speed really helps.
Before, he was hesitant to come down here, but seeing Ronnie act suspicious as he entered the sewer made Barry think of something.
Barry keeps his speed within his known limit; he still doesn't plan to expose to the team that he can speed blitz even Light if he wanted to.
He quickly covers every inch of Central City's sewage system, and he sees a lot of nasty things. Luckily, at his speed, he doesn't have to smell any.
But after running around for a while, he finally comes across something. Something that forces him to slow down and look at.
Walls full of writing, numbers, letters, drawings, even depictions of stories through drawings, these were clear signs of something growing in intelligence.
And Barry finally found the last piece of the puzzle. Grodd. The name is written on the walls over and over again.
'I knew he was being kept down here by Wells, but did Grodd take out Woodward, and now Ronnie, as well? Is Grodd strong enough to take out Firestorm?' Barry wonders.
Grodd might be a super gorilla, but Barry doesn't think he is fireproof.
So Barry continues his search.