After Ronnie kills a physicist, Barry and the team go after him. Joe enlists Cisco's help in the reinvestigation of Nora Allen's murder. Barry struggles with a new relationship and his duties as The Flash.
After the nuclear explosion separates Ronnie and Dr. Stein, Barry and the team believe both men are safe. Barry gets some important information about time travel.
Knowing it's a deliberate distraction from Dr. Wells, Barry and those at S.T.A.R. Labs can't help but deal with an angry, mind-controlling meta-gorilla.