With Ava left largely free to pursue her agenda, Nash puts himself and his remnant Wells minds on the line to try and restore Barry's speed. Meanwhile Iris faces a mirror universe where she cannot escape from herself.
Barry discovers that the artificial speed force has given him super-fast thinking, leading the team to a potential way to rescue Iris and Camilla – but first they much catch up with Eva McCulloch.
Team Flash desperately searches for a way to save Iris and restore Barry's speed, as Eva unleashes a full-scale Mirror invasion of our realm. A familiar face makes a startling return.
The villain Abra Kadabra returns from the far future with a vengeance, looking to settle a score with the Flash. Iris tries to settle back into work, but finds it difficult to move past her recent trauma.
As the team struggles to understand a shocking new manifestation of the speed force, a powerful telepath attacks the city and amplifies everyone's fears. Caitlin and Frost disagree over how to move forward in their new reality.
An encounter with a new force of nature traps Cisco and Chester in a small-town bubble in the year 1998, where Chester must face his father in the hopes of getting them home. Meanwhile, Iris makes a personal connection with the speed force.
Frost goes in search of a new ice-powered metahuman after a frozen crime scene points the new state investigator in her direction. Barry tries to come to terms with the speed force and her new presence in their lives.
After Frost submits herself to the justice system the team argues about how to save her from an unjust punishment for her past crimes – including the prosecutor's desire to take away her powers. Meanwhile, Barry and Nora's search for Fuerza leads to a surprising place.
After a personal betrayal Barry resolves to try and go back in time to prevent the forces of nature from being created, but finds himself at odds with those closest to him.
Barry and Iris investigate when Psych attacks someone from his past. While the team tries to train Alexa to control her abilities, Kamila and Cisco consider making a major move.
Barry and Iris try to hide Alexa and Bashir from the speed force in the one place that she cannot go – and convince Dion to join them. Nora summons a dangerous storm to threaten Central City.
Cisco struggles with his friends' apparently happy response to the news that he and Kamila are leaving Central City. Meanwhile a meta appears who is conducting a series of robberies by making her victims feel happy and uninhibited.
Cecile's life is taken over by an ancient force, who traps the real Cecile in a mental prison. As Joe investigates Kramer's military past, Chester experiences growing pains when trying to take over for Cisco.
Sue Dearbon returns amidst Allegra's efforts to find her cousin – the deadly assassin Ultraviolet, who is hunting the scientist who made her the way she is. Meanwhile, Joe gets a cold reception when he questions Kramer about her past.
Barry's enthusiasm about having a child with Iris is tampered by the arrival of an army of Godspeeds in Central City. Caitlin and Allegra try to help Ultraviolet recover herself, and Frost tries to prove that Chillblaine isn't as reformed as he claims.
With Central City under siege by a war between the Godspeed clones, John Diggle arrives with a little help from Argus – and a plan to trap the enemy. Allegra tries to talk her cousin out of a vendetta, and Joe and Kramer find themselves hunted by their target.
Nora and Bart Allen, Barry and Iris' children from the future, follow Godspeed from 2049 to the present day. But as the speedsters team up to end the enemy civil war, Bart's personal connection to August Heart threatens to tear them apart.
After a trip inside August Heart's mind reveals Godspeed's true agenda, Team Flash gets a super boost from the speed force in order to defend Central City. Joe and Kramer make a stunning discovery on their way home.