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.

When a powerful new villain, Psych, channels and amplifies everyone's fears in order to wreak havoc on Central City, Barry realizes, with Cecile's help, that he must face his own worst fear in order to beat this new threat. Meanwhile, Joe is surprised when Kristen Kramer from the Governor's Municipal Logistics Commission drops into CCPD for a visit. Iris warns her father to dig deeper on why Kristen is actually there. Caitlin and Frost argue about how to live their lives.

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.

Barry and Iris come together to try and stop a dangerous force from destroying Central City.

When Ultraviolet returns to Central City, Allegra is determined to find her cousin and change her heart. Meanwhile, Joe finds evidence that Kristen Kramer may not be the good cop she appears to be.

Barry and Iris greet their future children, XS and Bart, only for a shocking secret to threaten their new familial harmony. Meanwhile, the Godspeed war intensifies and threatens to destroy Central City.

Barry meets Black Lightning at the Hall of Justice after things take a dire turn with Despero. Iris suspects something is off with Despero's vision of the future so she seeks help from a powerful ally.

Barry is shocked when Eobard Thawne returns in the most unexpected way, and with a tie to a loved one. Damien Darhk offers advice to Barry but there is a catch. An epic battle begins with Reverse Flash pitted against The Flash, Team Flash, Batwoman, Sentinel and Ryan Choi.

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's desire to keep Team Flash safe is tested when Frost recklessly courts danger as she tries to stop the "Black Flame," meanwhile, Iris tries to help a teen girl reunite with her mother but unintentionally does more harm than good.

Team Flash is under attack, and each must fight to save not only themselves but each other.

The Flash gets blasted with a shockwave forcing his body to age prematurely.

The Flash and team are in for the fight of their lives, meanwhile, Iris discovers the cause of her time sickness.

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.

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.

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.