The third episode of the first season of 'The Flash' aired Tuesday as Barry Allen, played by Gustin Grant, faces off against The Mist, while Caitlin Snow, played by Danielle Panabaker, finds out that the fiancé she thought had passed on was still very much alive.

In the episode, "The Things You Can't Outrun," Barry and the team at S.T.A.R Labs work to capture villain of the week Kyle, a dangerous new meta-human with toxic gas powers. Things take a turn for the worst when Kyle decided to seek revenge on Barry's father-figure, Joe West, played by Jesse Martin, for having arrested him years prior to the start of series.

Meanwhile, Joe remains unaware of the budding relationship of his daughter, Iris, played by Candice Patton, with his partner in the police department, Eddie, played by Rick Cosnett. He also decided to pay a visit to Barry's father, Henry Allen, played by John Wesley Shipp, who was imprisoned for allegedly killing his own wife.

S.T.A.R. Lab's resident bio-engineer, Caitlin, has her own memories to face as she revisits the night the particle accelerator exploded and killed her fiancé, Ronnie. In an exclusive interview with Variety however, Amell, who plays Ronnie, revealed that he was not only very much alive, but also imbued with powers similar to Barry.

Amell, who previously played Stephen Jameson on the CW series 'The Tomorrow People', revealed that Ronnie was in fact DC Comics icon, Firestorm, who has powers over fire and heat. Just how much of Firestorm and his skills will be shown, Amell has declined to share.

"You don't know if I'm a good guy or a bad guy when you first find me," Amell stated of his character, "I think it's going to be pretty awesome."

The CW revealed the synopsis for the show's fourth episode, "Going Rogue," and according to Hollywood Hills more new faces will be appearing. Barry will reunite with Felicity Smoak, played by Emily Bett Rickards, from The CW show, 'Arrow'. Gustin had guest-starred in the 'Arrow' as Barry during its second season before The CW gave the greenlight to 'The Flash' as a spin-off series.

'The Flash' airs 8 pm Tuesdays on CWTV.