“Enter Flashtime” is episode fifteen of season four of The Flash.
A sweating Barry approaches a motionless Iris and touches her to bring her into flashtime. He says he can’t save them this time. They look at something.
8 minutes 489 seconds earlier and Barry is trying to get through Cisco’s breaches before they close to see if he’ll be able to follow DeVoe into his pocket dimension. They’ve been doing it for hours and Cisco decides to take five. Iris suggests a breather to Barry. Like date night. They’ve had no quality time together since the honeymoon. Barry is wondering why with them spending so much time together it doesn’t feel as if they’re spending it as husband and wife. Then Harry calls them to the Cortex.
They’ve got a map of every time DeVoe went in and out of his lair and where. Going on for three years. DeVoe has orchestrated everything to get the people he wanted on the bus. Now, they have to wait until the next time and keep an eye on Ralph. Then Jesse shows.
She and her father leave for his lab. She has an apology cube and says they work best if you record an apology on them. Jesse feels that Harry needs to deal with the death of her mother. He doesn’t want to talk about it still.
Joe and others are being fired upon in a hangar. The attackers are after something in a container. Joe calls an alarm. Iris brings the screen up showing the hangar; CCPD was helping ARGOS transport something. The container is blown open and a woman enters. She looks at something, then everything foes quiet behind her. Killer Frost, Vibe and Jesse Quick have taken her people captive and the Flash is behind her. Barry says it’s over. She agrees it is. For Central City. And activates something. Something nuclear.
Barry heads into the container and Jesse joins him. He says they are too late. She states the obvious. Barry says they need to keep moving and wants her to go get Jay Garrick. She leaves.
Barry touches Cisco, who says they’re way past the point of undoing it. Cisco suggests breaching it to a dead Earth like Fallout. However, this doesn’t work; they’re moving too fast for a breach to open. And Cisco’s body can’t handle this speed. Cisco says to ask Harry.
Barry brings Harry in to flashtime and fills him in. Harry says they can’t stop the reaction; send the bomb into the Speed Force. He doesn’t think it will affect it. Jesse returns with Jay and Barry lets Harry go. According to Jay, sending the bomb into the Speed Force might destroy it completely. Every speedster will lose their speed. They can’t do this. Barry thinks they might have to. Jay says the Speed Force is a fundamental part of the universe. Destroying it would be bad. He’s sweating.
There’s a nuclear explosion going to wipe out Central City and everything they try fails. Plus, the speedsters are running so fast they’re draining their reserves, and are running out of the ability to keep going. Things are not looking good.