This week’s episode starts in the midst of a snowy scene as Barry and Iris are hanging out around the fireplace at their apartment. Barry is working with equations quite frantically as he’s trying to solve the time he needs to go to to get more answers about Savitar.
Iris begins to take a serious tone and asks Barry to promise her that he’ll look after Joe and Wally should the Savitar kill her. An originally reluctant Barry eventually promises her that’ll he’ll be sure to look after them, be insists that they’ll stop Savitar before anything happens. Just then, his phone starts buzzing with an alarm.
At STAR Labs, Caitlin Snow — now officially Killer Frost as we saw in the last episode — appears to be running amok causing destruction. After a brief fight between Killer Frost and Cisco, Julian, and HR, Barry races in to save them. Killer Frosts creates an ice barrier to trap the four good guys as she makes her escape.
Cisco and Julian have a brief argument about Caitling/Killer Frost before Barry calms them down, only to inform the group that he plans on traveling to the future. Together Barry and Wally race to open up a singularity which Barry travels through to get to 2024.
As soon as he appears in the future, he picks up a newspaper to confirm what time he’s in and is immediately confronted by a pair of villains we’ve seen before — Mirror Master and Top.
After a very brief confrontation, Barry gets away from the two Rogues and Mirror Master states that “next time, they’ll put him something he can’t get out of.”
Barry travels to the apartment the two shared, which has been destroyed. Cisco comes in from the other room and gives Barry a hug, saying that he saw him on security cameras wearing the 2017 version of the suit.
The two go to STAR Labs, where Cisco reveals that Barry shut everything down once Iris was killed (in this future) and Barry goes on to the lower hallway to discover the rest of the facility as Cisco stays behind in the elevator.
In the lower hallway, 2017 Barry is approached by the Barry of the future, and the future Barry warns him that he’ll not be able to help. Current Barry begs an answer to who Savitar is and the future Barry is unable to answer, as he doesn’t know Savitar’s true identity. Future Barry recommends the time-traveling Barry return home to the current timeline and spend as much time as he can with Iris.
Barry then goes to the former jail area in an attempt to create a singularity so he can travel back home and much to his dismay, he’s unable to open up a breach.
Barry asks Cisco why he couldn’t open a breach and Cisco isn’t sure of the answer. Cisco then reveals that Killer Frost had frozen off his hands, effectively taking away his vibing capabilities.
Barry asks about the rest of Team Flash and Cisco takes him to visit with Julian. It’s revealed that Julian has incarcerated Killer Frost in one of the cells at his lab and Barry begins speaking with her, and Killer Frost says that she teamed up with Savitar as he gave her what she’s always wanted: to be who she really is. Barry realizes that she knows the true identity of Savitar, but she won’t tell him. She does, however, say that he’ll be very surprised once he finds out.
Cisco and Barry then goes to the West household to see Wally and are met by a caretaker. Barry looks into the living room and sees Wally sitting in a wheelchair and Barry reintroduces himself. Wally is revealed to have a shattered spine, as he went after Savitar himself after learning Iris had been killed. Cisco says that whatever Wally saw that night, it made him the way he is.
Barry asks where Joe is, and it’s revealed that Joe is at Iris’ grave. An upset Joe informs Barry that after Iris had been killed and Wally seriously maimed, the future Barry left Joe without any support. Joe asks Barry to leave the grave site.
Back at the future STAR Labs, the future Barry is looking at a picture of him and Iris in the original Thawne’s secret suit room. 2017 Barry goes to confront him and the two fight.
The future Barry reveals that eventually Savitar gets locked in the Speedforce, but it’s a moot point as everything Barry had every loved was taken from him. Barry rushes back to Cisco and begs for an answer on how to open up a breach so that he can travel back in time and Cisco reveals he doesn’t want Barry to leave.
Barry realizes that Cisco made it so he couldn’t go back to the past, because he wanted the two to work on getting Team Flash to get back together in the future. Barry goes to open a breach when he realizes he needs Cisco’s help. He goes back to Cisco and asks to for help, and the two agree that they also need HR Wells back as well.
It’s shown that Jitters has been renamed to “HR Jitters” and HR is now a novelist. Barry rounds HR, Julian, and Joe up and takes them all to STAR Labs and talks to them all about becoming a team again. Coincidentally enough, Cisco’s metahuman tracking app pings and Cisco announces the Rogues are in the middle of a robbery.
Barry meets the two in an alleyway and a fight ensues. They’re getting the better hand when the future Barry steps in says he’ll help. Future Barry races to the scene with a device Cisco created that renders the Rogues powers useless. The once and future Flash team up to stop the Rogues and tie them up.
Back at STAR Labs, the future Barry admit that he has a lot more work to do, but they’ve made the first big step at getting their team back together. Future Barry reveals that somebody by the name of Tracy Brand had helped him trap Savitar in the Speedforce, though the technology came four years after Iris was murdered.
The future Barry gives 2017 Barry a drive that has information from Brand and tells him to take it back and see if they can use it. Barry travels back to the current timeline and reveals to the team that Caitlin aligned herself with Savitar and they agree to go find Caitlin to stop her from teaming up with the God of Speed.
The episode closes out a shoe-less Caitlin Snow is seen meeting in the woods with Savitar, and the latter states that he wants to make sure Caitlin never returns. When Caitlin asks why she should trust Savitar, the person inside the suit steps out, although we only see their feet.