"The team attempts to track Ronnie's whereabouts after he injures a scientist. Knowing that Dr. Martin Stein is in control of Ronnie's body, they use his wife to talk Stein/Ronnie into coming back to the lab for testing. Meanwhile, Joe enlists Cisco's help to identify who murdered Barry's mother. Cisco discovers an old mirror left in the former Allen home that captured images from the night of the murder, and Joe finds blood from two people behind some new wallpaper, one of whom was likely the killer. Joe asks Cisco to compare the blood to Dr. Wells', but Cisco refuses to believe Dr. Wells is involved. Dr. Wells discovers that Ronnie and Dr. Stein's atoms are in conflict, and if it continues they will become nuclear. Dr. Wells determines that the tachyon device recharging his speed could be converted to a quantum splicer to stabilize Ronnie's body and separate the two personalities. Dr. Snow uses the device; Ronnie's body still goes nuclear, but safely away from the city. The explosion alerts General Eiling, who orders a team to recover F.I.R.E.S.T.O.R.M. Cisco runs the blood samples and informs Joe that while neither is from Dr. Wells, one is from an adult Barry."
So, we find out that adult Barry was at his mothers murder... not surprising to anybody familiar with the comic book. And we see the team try to separate Firestorm into his two component personalities. Which results in a nuclear blast that triggers the return of the military. Now I'm sure Firestorm survived the blast, and I'm gonna guess that he'll be more like the comic book version now, with both personalities able to speak and express themselves.