After catching a glimpse of Harrison Wells (Tom Cavanaugh) version 2.0 in episode 2 of the CW's "The Flash," fans watched the formerly evil scientist walk through the stabilized wormhole from Earth 2 into Barry's (Grant Gustin) universe at the end of Season 2, episode 3. While there is no reason to assume this Wells is evil -- Eobard Thawne did not take control of Wells' body in Earth 2, after all -- it would be better to be safe than sorry. So, it would sure be nice for S.T.A.R. Labs to have Firestorm back. What will happen in episode 4, "The Fury of Firestorm"?

According to the synopsis for the new episode, Dr. Stein (Victor Garber), whom fans saw violently bursting into blue flames at the end of episode 3, is in the market for a new partner for his Firestorm alter ego. Of course, fans remember that Ronnie Raymond (Robbie Amell), Stein's original other half, was killed helping Barry stop the black hole from destroying Central City in the Season 1 finale. Luckily, Cisco (Carlos Valdes) and Caitlin (Danielle Panabaker) might be able to find a meta-human match for the out of balance Stein -- Jefferson “Jax” Jackson (guest star Franz Drameh). However, Caitlin has doubts about whether they can trust their new ally. 

Plus, the synopsis reveals that Barry and Patty (Shantel VanSanten) will be growing a bit closer in episode 4. The newest member of Joe's (Jesse Martin) meta-human task force, gave her number to Barry at the end of episode 3 and admitted to having a crush on the forensics expert. With Iris (Candice Patton) and Barry shelving their feelings for now, the door is open for a new romance in Central City. 

Watch the promo for episode 4 below:

Will Jax Jackson prove a match for Firestorm? And can he be trusted? Fans will have to wait to find out. "The Flash" airs Tuesdays at 8 p.m. EDT on the CW.