When Barry suddenly gains the power of speed thinking, he attempts to use his new gift to save Iris; Cisco is hesitant to trust Barry's new power; Eva must face a shattering truth.
As Eva becomes more powerful, Barry and the team must find a way to stop her; an old friend risks her life to help.
Feeling overwhelmed with all the changes since Crisis, Barry conducts an experiment that goes awry and puts him directly in Gorilla Grodd's path; Iris works with Eva to escape the Mirrorverse.
After recent events, Barry examines his life with Iris a little more carefully; Eva decides to make a bold move.
After Black Hole hires Rag Doll to kill Joe, Singh suggests that Joe go into the witness protection program, while Ralph runs into Sue and Iris becomes suspicious of Eva.