Barry and Iris plan a romantic dinner for Valentine's Day but their evening is interrupted by an old foe - Amunet; Frost gets into the holiday spirit and attempts to help Allegra reconnect with an old love.

Kid Flash returns to Central City with a Zen attitude and new tricks up his sleeve. While thrilled to see his family again, Wally confides to Barry that he returned because he thinks there is something wrong with the speed force. Meanwhile, Cisco returns from his fact-finding mission across Earth-Prime.

The Flash takes on a dangerous new meta named Sunshine. Cisco sets out to help Nash.

After recent events, Barry takes a closer look at his life with Iris. Eva makes a bold move.

When Barry suddenly gains the power of speed thinking, he attempts to use his new gift to save Iris. While Barry is thrilled with his new power, Cisco is hesitant to trust it. Meanwhile, Eva must face a shattering truth.

As Eva becomes more powerful, Barry and team must find a way to stop her. They are shocked when an old friend - Sue Dearbon risks her life to help.

When a mysterious ice powered enemy frames Frost for a brutal crime, she must find a way to clear her name; Barry and Iris have a surprise houseguest, and Joe continues to deal with Kristen Kramer.

With Frost facing an unjust punishment for her past crimes, Caitlin goes to great lengths to save her sister. Meanwhile, Barry's efforts to protect Speed Force Nora lead to a shocking discovery.

When a powerful alien threat arrives on Earth under mysterious circumstances, Barry, Iris and the rest of Team Flash are pushed to their limits in a desperate battle to save the world. But with time running out and the fate of humanity at stake, Flash and his companions will also need to enlist the help of some old friends if the forces of good are to prevail.

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.

After returning home from a visit for their parent's vow renewal, Bart and Nora quickly realize that things are not exactly as they left them. The duo race to repair any fissures in the timeline and restore everything back to the way it is supposed to be.

When a criminal invades the CCPD, Barry and Kramer must trust and rely on each other if they are going to make it out safely. Meanwhile, Caitlin learns a valuable lesson while out with Snow and Mark.

Barry trusts his instincts during a murder investigation, believing the suspect, despite the overwhelming evidence against him, meanwhile Iris gives Allegra an opportunity to be a mentor.

With a new Meta terrorizing the city, Joe lends a hand to the local authorities, meanwhile Barry gets an assist from Cecille who helps to track the mass murderer.

Team Flash uses the distraction of a bank robbing Meta to detract from the grief of losing someone they love.

The Flash goes off the grid to look for answers about a new Meta in town. Meanwhile, Allegra pulls out all of the stops at CC Citizen Media, to protect a source and a friend.

Barry creates a map book to guide him and Iris throughout their future in order to keep her safe, but the results are not what he expected, and instead, they relive the same day over and over again. Joe has a heart-to-heart with Cecile. A new big bad is introduced to Team Flash and friends and foes, old and new, begin to descend upon Central City.

As the Red Death wreaks havoc on Central City, Barry and Iris come up with a plan and turn to Cecile for help. Barry is faced with what he thinks was his greatest mistake and the Red Death's greatest success. Khione wants to help Team Flash, but Barry can't risk losing her. Joe gives Barry a much-needed pep talk.

Iris is visited by Nia Nal, as she needs Iris' help. When Iris and Nia fall into a fever dream and explore different possibilities for their lives, Barry, Chester, Allegra, and Cecile desperately try to help them. Meanwhile, Mark entertains Khione, but they have different ideas of what is fun, leaving Khione to feel that Mark is trying to make her something she is not.

The Flash, the fastest man alive, is tasked with his greatest challenge yet, to save the timeline and save existence. Friends old and new gather for an epic battle to save Central City, one last time.