“Fury Rogue” is episode nineteen of season four of The Flash.
Harry is double-checking with Gideon. It seems his use of the thinking cap in the previous episode, “Lose Yourself”, and the excessive infusion of dark matter means he’s losing his intelligence. At some point soon, he will have to relearn everything he knows. And it’s unlikely the thinking cap can fix this, as it, and dark matter, caused the problem.
Iris and Barry are seeing Dr Finkel. They are talking about Ralph’s death and Barry is saying he’s dealt with a lot of death and knows how to deal with it. Dr Finkel tells him that practice doesn’t make perfect when it comes to grief.
Marlize has brought DeVoe, now looking like himself again, a drink. He was going to dose hers, but because she seems happy, refrains. She’s glad to have him back in his familiar shape, and Ralph’s body can cope with the dark matter. DeVoe wants them to start on the next step today. Marlize thought they could spend some time as husband and wife. DeVoe tells her to leave the thinking to him.
Cisco is looking at the thinking cap. Harry tells him it doesn’t work. Cisco thinks they stopped Harry from using it when they needed it most. Harry says DeVoe is still smarter. Cisco thinks they could stimulate his brain with it. Harry tells him that it’s tuned for Harry’s brain. So, Cisco suggests making a second for him. TYwo caps to be smarter than DeVoe.
Caitlin is watching the video where DeVoe drained Killer Frost’s powers when Iris joins her. Iris says that DeVoe had no interest in any metas other than the bus metas, so why would he want Caitlin’s powers? Caitlin thinks it must have been DeVoe. Then an alarm goes off.
Three different pocket dimensions opened up, all near where Fallout is being kept safe. They decide they need to transport Fallout elsewhere, and cool him down to keep him safe. Cisco has a prototype cold gun, but it will need a day to finish. And they need to see if they can do something DeVoe won’t think of.
On Earth-X, Citizen Cold is going after one of the few surviving New Reichsmen. The woman knocks him down with a sonic blast but Barry speeds in and gets Leo before she can finish him. Cisco breaches them out, but the woman follows without their knowledge. And reveals she’s Earth-X’s Laurel Lance. Back home, they explain the situation to Leo and that they came to him primarily because of his cold gun. He can give them 24 hours. Because he’s marrying Ray tomorrow.
The new thinking cap is ready and Cisco tries it out. It works, then overloads, and Harry tells him that they don’t have a replacement for the piece that fried and won’t for several weeks.
DeVoe planned to get Team Flash to move Fallout. However, they aren’t going to the location he predicted. Marlize is wearing his favourite dress. He’s not interested. And tells her not to think again. Until the enlightenment, her sole role is as his technician. They need to motivate Barry to send Fallout where was originally planned.
Barry is talking to Leo about Ralph. Leo thinks that Barry needs to grieve Ralph’s death, just as Leo did with every single rebel death. Joe and Iris enter; they’re ready. And the other Laurel Lance is listening.
DeVoe is still manipulating them into doing what he wants. But, though they don’t realise this, finally something happens that he didn’t predict. Because there’s something he seems to have lost the ability to comprehend.