Cisco's faith in his ability to fill Barry's shoes as Team Leader is upended when he learns of a shocking murder. Meanwhile, Killer Frost trusts no one except herself to hunt down the dangerous Ramsey Rosso.

After a devastating betrayal, Barry turns to Timeless Wells for help. Meanwhile, Iris leads Team Citizen down a dangerous road in search of answers, and Cisco confides his biggest fear to Kamilla.

Despero warns The Flash that great tragedies will befall the speedster and cause him to lose his mind. Once that happens, Armageddon will begin. Determined to prove Despero wrong, Barry doubles down on proving his innocence but a devastating revelation from Iris pushes him to the edge and sends him to seek counsel from Black Lightning.

An opportunity presents itself for The Flash to end his lifelong battle with Reverse Flash for good, but the payoff could be too much for Barry and team to handle. Meanwhile, Mia Queen drops in from the future looking to save a lost loved one, and she won't let anything stand in her way.

The Flash is forced to make an impossible choice. With the power out in the city, Team Flash calls upon the Rogue Squad to help as Iris is visited by an old friend. Joe and Cecile work on finding a balance.