The episode starts with the Earth 90 scene that was on the end of all the episodes last week.
The next scene introduces us to Doctor John Deegan, who wants to help mental patients through eugenics. Thankfully, this still makes him a supervillain. After all his colleagues throw this back in his face at a conference, the Monitor shows up in the parking lot and says that he needs Deegan’s help. The Monitor gives him the previously seen glowy book and tells him to rewrite reality with it. Deegan opens it.
Oliver wakes up in Barry’s loft. He’s in the pictures and Iris thinks he’s Barry. Oliver says that he didn’t get enough sleep. Iris suggests that he take the day off, but that is not to be. There has been a break in at Ivo Industries and someone is trying to steal diamonds. Oliver realizes that he has speed and Iris tosses him the Flash ring. While Oliver is kind of enjoying himself, he thinks that this is all Barry’s fault.
Watching Oliver try to stop a bank robbery as the Flash is hilarious, because he has no idea what he’s doing. He gives the robber the Arrow line, realizes that he can outrun bullets, and does some serious overkill with a lightning punch. He even wakes up a robot.
Caitlin checks him out in the infirmary and says that he’s fine. Oliver is uncomfortable with all the PDA, which everyone finds odd. There’s also some high key shade on the hallway pep talks that the Flash uses. What Oliver wants instead is to talk to “Oliver.”
Barry is being beat up by Diggle at A.R.G.U.S. Diggle thinks he’s Oliver, and Barry is significantly more excited than Oliver was. That is, until they have a mess to clean up and he doesn’t know how to put on Oliver’s outfit.
Barry doesn’t have the same hand to hand combat expertise as Oliver, but he does alright until the end, where Oliver shows up to help. Diggle throws up.
Barry is excited about what’s happening until he finds out where Oliver woke up this morning. Then he agrees that they need to fix this as soon as possible.
They go to S.T.A.R. Labs to do just that, but there is a problem. No one believes them.
Barry tells Oliver that he needs to convince Iris. Oliver tries to get some help from alcohol but doesn’t know Barry can’t get drunk. Then Iris proceeds to go off on Oliver. Felicity apparently called her while Oliver was in prison. It’s nice that there’s a superhero wives club, but it’s highly awkward that Iris is going off on Oliver, unknowingly, to Oliver. It’s also weird that she drugs him with nanites while Ralph knocks Barry out.
They both wake up in the pipeline. Barry has a plan. If they can get an extrapolator, they can ask Kara for help and see if this is purely an Earth-1 problem.
Cisco is trying to contact A.R.G.U.S but is getting interference from a storm: red skies and yellow lightning. He then accidentally vibes the Monitor.
Oliver wants to back up the toilet and fry the meta dampener. He tells Barry how to get out of handcuffs, which of course involves breaking thumbs. Barry eventually does this and fries the dampener. He then tells Oliver how to phase out of the cuffs and the cell.
They get to Cisco’s lab only to find that Iris has the extrapolator. Barry convinces Iris to give it to them and they go.
THEN THE SMALLVILLE THEME SONG PLAYS OVER THE KENT FARM IN KANSAS AND MY NERD HEART IS FULL!!! Clark, Lois, and Kara are doing farm things and arguing about whatever drama has been going on on Supergirl lately. Lois wins and goes to fix something in the barn.
Clark and Kara continue to talk about aforementioned drama which includes Cat Grant being scarier than the President and Kara no longer working with the DEO.
Kara then has to introduce Oliver and Barry before Lois kills them. She recognizes which is which and introduces them to Clark and Lois. Barry fangirls a bit and Oliver showcases the problem.
Back on Earth 1, the robot that Oliver woke up is causing a bit of mayhem. Ralph and Killer Frost try to take care of it but can’t. It also adapts to their powers.
While Oliver is training Barry with paint cans, Barry gets revenge on Oliver for the time that Oliver shot him. Oliver is ticked, but not because he got shot. He’s ticked that Barry is having fun with this. He tries to provoke Barry, but Barry doesn’t bite.
The killer robot’s name is Amazo and it was created to find metas, which is does through a version of the mirakuru serum. Somebody put mirakuru in a robot, or if you want to get really technical, an android. Sherloque found Iris and she tells them that she let Oliver and Barry go. They now believe them through her. Cisco tells them about the Vibe.
Amazo enters city limits and starts looking for metas.
Oliver and Barry talk. Oliver learns from pain, so Barry having fun with his abilities ticked him off. Barry runs towards joy. They both need to act like each other in order for this to work. Kara is glad that they’ve figured this out.
Cisco pops in and tells them that everyone believes them now and that they have a huge robot problem. Kara and Clark decide to come help too. Lois calls Clark Smallville, he’s wearing the suit under his flannel, and all is right with the world.
They fight the robot and it’s awesome. They try to keep it off balance long enough for Superman to finish it off. He appears to do so, but Amazo comes back for round two. He now has all their abilities and all their symbols.
Sherloque tells Team Flash that they need to turn it off. This gives Barry an idea. If Oliver can bring it back around, Kara and Clark can hit it. It can’t run and phase at the same time.
Team Flash gets the idea to make a virus, but the question is how to insert it. Kara hits it as it chases Oliver. She and Clark hold it down while Oliver phases and Barry shoots the virus. Barry says the Arrow thing and Amazo explodes.
Sherloque asks Clark to deliver an alimony check to his third ex-wife.
Barry and Iris talk. She’s worried that he’ll become Oliver Queen. He promises not to.
Cisco tells Barry, Oliver, and Kara about his vibe. He then vibes Oliver and Barry. The Monitor can see them and is impressed. Cisco has to go tend to a nosebleed, but Oliver draws what they saw for Kara. They’re going to Gotham.
Batwoman is standing on top of a tower, looking all broody.
I only have one problem with this episode. When did Iris get so down on Oliver? I will rate this once the crossover ends.