Versus Zoom
Flash figures out how to travel back to Earth-2 using Cisco’s vibing powers. Discovering that Jay is really Earth-2 serial killer Hunter Zolomon, whose father killed his mother in front of him as a child, Barry devises a plan to lead Zoom on a chase across the city to STAR Labs and disorient him using images of his parents. Believing he’s trapped Zoom with a speed suppressing device, Barry gloats until Zoom escapes and kidnaps the clueless Wally, ransoming him in return for Barry’s speed. But Wally is family, and Barry is always prepared to make the ultimate sacrifices for his family. They invite Zoom back and trade Wally for Barry’s speed. Once Zoom absorbs Barry’s speed he attempts to kill him, for fun apparently, until Caitlin pleads for his life. Zoom lets Flash go but takes Caitlin away with him. Barry, now without his speed, has no way of pursuing or helping Caitlin.
Zoom
When Caitlin offhandedly mentions that Jay’s doppelganger on Earth-1 is named Hunter Zolomon, Harry overhears and reveals that Earth-2’s Hunter Zolomon is a notorious serial killer. Flash is able to use this information against him, finding images of his parents and using them as emotional ammunition to slow him down in their chase. Of course, Zoom is not to be underestimated and knows just who to go after to force Barry’s hand. As for Jay’s apparent death, Jay explains that he went back in time to an earlier version of himself and convinced him to let him bring him to the future to murder him for their plan. Jay is, after all, a psychopath and just having Barry’s speed seems not to be enough for him without also killing Barry. Caitlin, always an extraordinary woman who seems to mean a great deal to everyone she interacts with, appeals to Jay’s feelings for her, begging him not to kill Barry. While he lets Flash go, he obviously has to take Caitlin with him instead.
Wally
Wally’s become a real member of the West family – visiting on his breaks from school, bringing home laundry to do, the works. He mentions that he’s not living on campus anymore because it’s too expensive and Joe offers to help pay for it. Wally declines, seeming uncomfortable and disappointed. When Joe and Barry talk about it later, Barry explains that Wally doesn’t want Joe to pay for a place to live, he wants Joe to offer for Wally to live with him. It’s decided later that Wally is going to move into the West house, which means that Zoom knows exactly where to find him when he wants a hostage.
Iris and Barry
Iris, intending to move on after Eddie’s death, has set a date with her editor, Scott. Barry asks her to stay and help with the breach problem, but when she tells him about her date he is awkwardly supportive. Iris, in turn, is obviously uncertain. When she talks to Caitlin later, she tells her that she ended up canceling her date. Caitlin, ever observant and intuitive, asks if it’s because of Eddie or because of Barry. Iris admits that she’s been wondering if she’s actually meant to be with Barry, that everything seems to be pointing to them being meant to be together. It seems like Barry’s inevitable vacation from being a speedster might be a good time to explore those feelings.