Tonight’s episode starts off with Barry and Wally meeting on an empty street, where it’s revealed that Cisco had some up technology to monitor the race they’re about to have.
Back at STAR Labs, Cisco mentions he has 5:1 odds on Barry and Iris puts $20 on Barry winning the race while Caitlin bets $80. HR bets $100 on Wally, after mentioning that back on his earth, Abe Lincoln is on the $100 bill.
As the race nears the end, Barry phases through a building that Wally has to go speed around, allowing Barry to win the race.
Barry, Joe, and Julian are seen in a diner where they’re investigating a decomposing body, even though the person has been dead just eight hours. Barry mentions taking the body to STAR Labs to investigate, much to Julian’s dismay. After a quick persuasive nod from Joe, Julian agrees with their plans to take the body to STAR Labs.
Back at STAR Labs, Iris points out to Barry that the attack at the diner will more than likely close the restaurant down, one of the items that came true in the future in which Savitar murdered Iris. Barry mentions to Iris that they should tell Joe about the future, but Iris quickly turns that idea down. Barry reassures her that he’ll do whatever it takes to make sure she lives.
Julian and Caitlin open up the body bag to examine the decomposing corpse and find it decomposed even further, something of which no disease can manage to do.
A singer named Julio Mendez is seen leaving a concert venue after a show where he’s approached by a man offering him a handshake. After he shakes the stranger’s hand, his arm begins decomposing, much in the way we saw the body at the diner.
We’re taken back to STAR Labs where Barry, Cisco, and HR are seen trying to train Wally to finally be able to phase through solid material. Wally runs straight towards to wall Barry just phased his arm through and is knocked back, unable to phase.
Barry’s phone buzzes as he’s called to the crime scene that Mendez is at. Barry informs Joe and Julian that Mendez was the CCPD captain in Flashpoint, the second cop that was in Flashpoint to be killed. Barry speeds Julian and the corpse away from the scene and Barry comes back and tells Joe that he needs to law low for a while.
Caitlin and Julian begin looking at the corpse back at STAR Labs and the two begin bickering back and forth about autopsy protocols. They analyze the DNA of the corpse where it’s revealed that the metahuman killing these people have the DNA of the husks Alchemy used to transform new metahumans. Julian realizes that he’s responsible for creating the new metahuman murdering people.
Barry, Wally, Joe, and Iris are at Jitters when Caitlin and Julian call Barry to warn him they’ve matched the DNA to Clive Yorkin and at that moment, Yorkin walks into the coffee joint asking for Joe West.
While Yorkin begins walking towards Joe, the latter opens fire and as the bullets touch Yorkin’s skin, they disintegrate. Wally speeds away and comes back suited up as Kid Flash and uses his arms to create a vortex that blows Yorkin away.
The team assembles back at STAR Labs and Iris finally breaks the news to Joe about the future in which Savitar kills her. A visibly upset Joe asks the team how long the team has known and after accosting the team, storms out of the room quickly followed by Iris. Caitlin and Julians share a moment in which Julian reflects that he feels guilt for creating the metahuman.
Iris is back at her and Barry’s apartment when she looks up to see her door begin dissolving and Yorkin walks through. She sets off her panic alarm and Wally speeds off but is too slow: Yorkin touches Iris’ arm.
At STAR Labs, the team begins discussing options and it’s decided that Iris’ arm must be frozen. The team realizes that Caitlin can use her powers to freeze Iris’ arm and after persuasion, Caitlin uses her powers. It works and stops the spreading of the decay.
Wally walks off, mentioning to the team that he needs to not mess up again. Barry follows in pursuit and gives Wally a pep talk about using his powers to succeed. Cisco busts in and tells the two speedsters than he and HR came up with a way to track Yorkin.
Cisco and HR tell the group that they have to vibe Flashpoint to see where Yorkin will be heading next. Barry reminds them that Flashpoint no longer exists before the pair tells Barry that Flashpoint may be happening on one of the other infinite number of earths.
Cisco puts on his glasses and begins vibing Flashpoint. He sees Joes and Julio Mendez as the captain as Officer Stone brings Yorkin in through the police department, parading the arrest. Joe realizes that the police officer Cisco vibed is a private investigator and rushes off to find where she’s at. He finds Stone at the train station and informs her of the apparent danger and they bored a train as Yorkin looks on from a distance.
Barry and Julian begin talking about fixing Iris’ condition and Julian tells Barry that her blood is attacking herself. Iris’ vitals start going up as Barry and Julian rush in to see Caitling trying to stop the decay with her powers. As Barry looks up at Caitlin, he sees her eyes change to white, the color they were in Flashpoint as Killer Frost.
Caitlin’s Killer Frost persona and Julian get into it about their prior conversation about the things they’ve done as their evil alter-egos and Julian persuades her to help out for the greater good.
Joe and Stone are seen on back on the train and Yorkin begins disintegrating the support beams the train is traveling under. Yorkin puts a pile of rubles on the train tracks as Joe sends out a distress signal. Barry and Wally show up and they realize that there’s not enough time to move the rubble or get everyone off the train, Barry decides he must phase the entire train through the rubble. Barry hops on the train and completes the phase as Yorkin approaches Kid Flash.
Barry tells Wally that he needs to phase some of his own bloody into Yorkin and although he’s never phases before, Wally completes the phasing process. Yorkin grabs Wally by his sleeve, proving that the phasing has worked.
Iris wakes up and ask what happens. HR mentions that “Wallace was a complete badass,” as Cisco explains the science behind phasing Wally’s blood into Yorkin. Julian then mentions that they were able to make an antidote. Joe talks to Iris and says that if they’re going to take on Savitar, the team can’t hold any more secrets.
Julian begins to leave STAR labs telling them he intends to find the last husk metahuman wondering Central City while Caitlin follows and mentions that she believes there’s really a good guy inside him that they’d like to see more. She then asks him out for a drink and he accepts.
Barry is seen installing a new door at his apartment with three extra locks and mentions to Iris that he just wants to make her feel safe and she tells him that she loves and trusts him.
The episode closes out as Wally is seen practicing phasing his arm through a wall s a breach opens up and Jesse Quick speeds through. She tells Wally that Grodd has kidnapped her dad.