On Earth-90, dozens of heroes' bodies lie scattered around. Flash crawls to a book, but a caped figure picks it up and tells Flash that he failed. Flash asks why the figure is doing it, and the figure says that he did it to himself and now all of them will perish. He opens the book, and Flash speeds away.
On Earth-1, Dr. John Deegan addresses a psychiatric consortium and talks about how his patients feel inferior and some people are born lucky. He talks about imperfection and says that they can utilize eugenic insights. One doctor dismisses him as Dr. Frankenstein and leaves, and others go with her. Deegan begs them to listen to him, but they go anyway. Outside at his car, a figure appears and says that he needs Deegan's help. The figure—the Monitor—says that he has traveled through time and space to give Deegan a book and show people what a real god can do. Deegan wonders why the Monitor chose him, and the Monitor says that Deegan has vision and all he has to do is open the book. When Deegan does so, a glow that the universe is in his hands. He advises Deegan to think bi is in his hands. He advises Deegan to think big.
At the loft in Central City, Oliver wakes up in Barry's bed and wonders where he is. Iris calls him out to the kitchen where she's making breakfast. There are photos of Oliver and Iris together, and Iris kisses a surprised Oliver. He asks where Barry is, and Iris says that he's Barry and talks about Cicada. Oliver plays along and Iris suggests that he call Singh and ask for a day off. An alert comes in about a break-in at Ivo Labs. Once Iris leaves to deal with it, Oliver discovers that he has superspeed. As she goes, Iris tosses Oliver is Flash ring and he dons the Flash costume and stares at himself in the mirror... and figures that Barry has done something.
Cisco radios to Oliver and tells him that the thieves are stealing diamonds used for conductors. When Oliver finally locates the place, he goes inside and confronts the two thieves. One of them has a hostage, and Oliver instinctively reaches for his arrows. Cisco tells him to use a lightning punch, and Oliver speeds past the thieves and into a wall. They open fire on him, and Oliver reacts at superspeed, dodging the bullets and hitting the thieves with a lightning bolt. It ricochets around the chamber and Cisco suggests that he let the cops takeover. As Oliver speeds away, an android emerges from the wreckage.
At Star Labs, Caitlin scans Oliver at his insistence. She assures him that he's fine, and Oliver suggests that he and Iris lay off the public displays of affections. They assure him that "Barry" is okay with them, and Oliver says that he's going home to think. The others figure that something is definitely up and ask if he needs to talk about what's bothering him. Oliver says that he's going to see Oliver Queen and speeds off.
In Star City, Barry and Diggle are sparring. Barry has no idea why he's there, and Ramsey perceives him as Oliver. Using his new fighting skills, Barry knocks Diggle down and afterward, checks the bruises on his chest. He tells Diggle that he needs to call Star Labs, ad an alarm goes off saying that the Bratvas are fighting over an old Diaz weapons cache. Diggle asks Barry for his help, and he has no choice but to agree.
Diggle and Barry go to the weapons cache and attack the men, and Barry drops in and attacks them directly. When some of them try to escape in a van, Barry fires an arrow. Oliver speeds in and whisks Barry and Diggle outside,
Later at the bunker, Barry practices on the salmon ladder while Oliver tries to work out what's going on. They confirm that all of the historical records show that they've switched places, and Barry takes things seriously when he realizes that Oliver woke up in Iris bed.
Back at Star Labs, Oliver and Barry explains the situation to Team Flash. Caitlin and Cisco scan their brains and tachyons confirm that there's nothing wrong. Team Flash talks privately, and Oliver assures Barry that he didn't touch Iris. He wonders how they're going to convince Iris to believe them, and Barry instructs Oliver in how to convince her. Oliver reluctantly goes out and drinks some wine, and Iris says that that Felicity called her and explains how "Oliver" went behind Felicity's back to make a deal with the FBI, and she's hurting. Iris tells him that "Oliver's" life is defined by anger and vengeance, and that's why she loves "Barry". Oliver waves and passes out, and Iris says that there were nanites in the wine and they need to get him to a safe place. When Barry sees what happened and tries to leave, Ralph punches him unconscious.
Oliver and Barry wake up in a pipeline cell with power suppressors on. Barry suggests that it might just be Earth-1 that's affected, and suggests that they get to Earth-38 and find out if Kara can see them for who they really are.
Cisco tells Caitlin that red light frequencies are blocking his transmissions to ARGUS, and Caitlin goes to run their scans again. Once she leaves, the power flickers and a voice advises him to give up. Cisco gets a vibe of the Monitor and wonders who it is.
Oliver complains about the lack of a toilet, and Barry realizes that he wants to back up the pipes and short circuit the dampeners. Barry has to dislocate his thumbs to reach the valve, and Oliver tells him to man up and do it. Much to Barry's surprise, it works and he turns off the valve to take off the dampener. Barry then tells Oliver how to phase out of the cell. Oliver laughs at how goofy Barry's thumb look, and Oliver phases through the cuffs and then the wall. The two of them go to get the extrapolator, and Iris steps out and says that she can't let them do it. Barry tries to get through to her, and describes when he moved in. Iris realizes that he's telling the truth and gives him the extrapolator, and they breach to Earth-38.
At the Kent farm in Smallville, Clark and Lois are working on the truck and arguing. Kara refuses to get involved, and Lois says that she'll make up a reason for why she went to Argo City with Superman. Once Lois leaves to do some work, Kara has beers with Clark and talks about how Baker challenged her to reveal her secret identity. She wonders if she did the same thing, and Clark assures her that their secret identities are important.
As Clark talks about he went to Argo City to reconnect with his culture, and had Lois with him, Barry and Oliver materialize. Kara recognizes them as who they really are, and introduces her cousin Clark. They explain what happened and ask Kara for her power.
The police calls for backup as the android breaks loose. It knocks out Killer Frost and Cisco when they arrive, and uses Ralph's power to knock out a guard and then flies off using Killer Frost's powers.
Oliver instructs Barry in how to shoot, insisting that he needs actual combat training. Barry suggests that Oliver run at him and he'll shoot at him, and Oliver agrees. Oliver catches the arrow but the remote-control bows that Barry hid shoot Oliver and Barry takes photos. Offended, Oliver invites Barry to get one hit at him and Lois, watching, yells in support because Oliver is a jerk. Oliver keeps taunting Barry, saying that Team Flash betrayed Barry. When Oliver comes at him, Barry flips him over.
At Star Labs, the team confirms that the Anti-Meta-human Adaptive Zootomic Organism: AMAZO. Ivo Labs was contracted by Argus to build a unit that could scan for metapowers, and it used a Mirakuru hybrid to copycat them. Iris tells them that she let Barry and Oliver go after "Oliver" convinced her that he was Barry. Cisco believes her, figuring the red skies and his vibe of the Monitor are connected to it. AMAZO enters city limits and smashes through a building, and heads for city hall.
Oliver approaches Barry, who says that he's been doing what he did for a long time and every time he learned something, it came with a painful memory. He admits that he draws on dark memories and seeing Barry joking pissed him off. Barry talks about how he runs he lets all of his grief go, and Oliver points out that Barry couldn't dislocate his thumb until he got angry. They agree that they need to act more like each other. Kara overhears them, comes out, and tells them to act the parts.
Cisco arrives via a breach and says that the team believes them. He tells them about the killer robot destroying Central City and they need help, and Kara and d Clark go with them.
As AMAZO lands at City Hall, Flash, Green Arrow, and Supergirl arrive at City Hall and attack AMAZO. They try to keep AMAZO off-balance before it can replicate their abilities, and Superman flies down and slams the robot into the concrete. AMAZO recovers, scans them, and duplicates their abilities. It phases through Superman's punches and then attacks them with their own powers, then goes hunting for more powers. Sherloque tells the team that it's a computer so should they turn it off.
Once AMAZO flies off, Barry says that they should bring it back. Oliver speeds off after it, and Barry tells Superman and Supergirl that it won't be able to phase and run at the same time.
Oliver pursues the superfast AMAZO through the city, dodging its attacks and luring it into a construction site where it inadvertently brings it down around itself.
Cisco and Caitlin create a virus to target AMAZO's operating system. Iris figures that AMAZO adapted all of their weaknesses as well, and Barry tells Oliver to counteract AMAZO's phasing while Supergirl and Superman hold it. Cisco brings Barry the virus, and he loads it into an arrow. Oliver lures AMAZO to Superman and Supergirl, and they grab it while Oliver negates its phasing abilities. Barry shoots the arrow and the virus into AMAZO, destroying it.
Later at Star Labs, Cisco announces that AMAZO has been disassembled. Kara points out that Barry and Oliver did fine with their opposite powers, and Iris wants them to get switched. Clark needs to head back to Earth-38, and Sherloque asks him to give his ex-wife there an alimony check.
Barry talks to Iris and asks if she's okay. She wonders what it cost Barry to defeat AMAZO, pointing out that when she let them go earlier, she realized Barry was and will always be the man she loves. Barry assures her that he'll always show her his true face, and Iris asks him to promise that when he finally gets his speed back, he'll come to her. She points out that he's Green Arrow now and asks him not to become Oliver, and Barry assures her that he won't.
Cisco calls Barry to the workshop and Cisco figures that the Monitor was involved with the mind-swapping. Oliver says that they need to see it, and Cisco shows them his vibe of the Monitor approaching Deegan and giving him the book. The Monitor realizes that Cisco is watching him, and says that nothing they can do will alter what is going to happen. Cisco gets a nosebleed and walks away, and Oliver draws the cityscape they saw: Gotham City.
In Gotham City, a caped figure stands atop a tower.
Written by Gadfly on Dec 10, 2018