The adventures of scientist Barry Allen who is a superhero with incredible speed.
Cast: Grant Gustin, Candice Patton, Rick Cosnett, Danielle Panabaker, Carlos Valdes, Tom Cavanagh, Jesse L. Martin, Patrick Sabongui
With nothing left to lose, Barry faces Savitar in a final showdown in Earth 19.
Barry chooses to use any means necessary to save the woman he loves; The Flash turns to Captain Cold for help.
Barry takes desperate measures to stop Savitar, while H.R. keeps pressuring Tracy Brand to set a trap for Savitar and Killer Frost has an interesting proposal.
Team Flash meets a scientist who may be the key to stopping Savitar, but is forced into a battle with Killer Frost.
Barry travels to 2024 to find out Savitar's still unknown identity in the hopes of saving Iris. He encounters future versions of his Team Flash friends, who, following the death of Iris, have become very different people. Meanwhile, back in the present, the hunt for Killer Frost continues.
The Flash fights a villain from Earth-19 called Abra Kadabra, who offers to reveal Savitar's identity in exchange for his release.
The Music Meister sends Supergirl and the Flash to a world where life is a musical and the only way to escape is to sing and dance.
Desperate to stop Savitar and save his friends, Barry turns to the speed force for answers; H.R. gives Jesse some advice.
While training with Barry, Wally starts to have visions of Savitar, which he hides from the team. A dangerous secret threatens Barry and Iris' happiness.
Grodd and his army of gorillas bring the battle to Earth-1, but the Flash and his team try to stop them before they destroy Central City. Meanwhile, Gypsy returns to join the fight; and Jesse Quick decides she wants to stay with Wally on Earth-1.
Barry and the team travel to Earth-2 to rescue Harry from Gorilla City, where they're captured and brought to Grodd, who claims he needs their help to stop Solovar.
A criminal meta-human is causing people to decompose at an accelerated rate.
H.R.'s past catches up with him when a bounty hunter with vibe powers named Gypsy arrives in Central City to bring him back to Earth-19 to stand trial for his crime. It turns out inter-dimensional travel is illegal on their Earth. H.R. surrenders but when Barry and Cisco find out that H.R.'s only hope would be to challenge Gypsy to a fight to the death, they intercede and Cisco offers to fight Gypsy instead
Barry is tormented by his vision of the future where Iris is murdered by Savitar. When a criminal named Plunder shows up in Central City, Barry recalls the villain's presence in his vision of the future and fears that if he catches Plunder it will cement Iris' fate. Confused about Barry's hesitation to stop Plunder, Wally decides to step in as Kid Flash. Meanwhile, Caitlin offers Julian a job.
Barry heads for Earth-3 to get advice from Jay Garrick on how to stop Savitar; Wally tells Barry he's been training with H.R.; old wounds are reopened as Cisco faces Christmas without Dante.
Barry asks Green Arrow for help when aliens attack Central City, but when they realize that won't be enough, they track down the Legends of Tomorrow so they can bring Supergirl in on the battle.
Caitlin uses her powers to save Barry but, as her mother predicted, the effort unleashes her inner Killer Frost. Killer Frost then goes on a rampage looking for Dr. Alchemy, kidnapping Julian and battling both the Flash and Vibe. Meanwhile, Joe and H.R. have a heart-to-heart talk.
When Wally starts having dreams about being Kid Flash, Barry realizes he has to tell Wally, Iris and Joe about what happened to Wally in Flashpoint in order to keep him safe.
Caitlin visits her mother to help her understand her growing meta-human powers; Barry tries to convince Julian to let him help investigate a new meta-human attacking Central City.
Barry continues to train Jesse and when a new meta human, Mirror Master, appears on the scene he lets her tag along. But she defies one of Barry's orders, which leads to disaster. Meanwhile, Mirror Master teams with his old partner, Top, and looks to even a score with Snart.
Just as Wells and Jesse return from Earth-2, Central City is attacked by a new meta with the power to control metal.
Barry discovers that the effects from Flashpoint are greater than he thought. In the meantime, he meets his new co-worker who has an immediate disdain for him.
The Reverse-Flash taunts Kid Flash, and warns of repercussions if Barry continues to forget his old life; when disaster strikes, Barry must decide whether to live as Barry Allen or return to his universe as The Flash.