A new villain shows up in Central City. He's stealing tech from various labs. Barry attempts to capture him, but he uses a magic trick to get away. Gypsy arrives. She's been chasing him, too. He's killed people on her Earth, but he's originally from the 64th Century. He knows all about Barry, including that Savitar kills Iris in the future. Since Gypsy's looking to put him to death, Kadabra wants to make a deal with Barry: if he lets him escape, he will tell him who Savitar really is.
Gypsy's not on board with that deal. She admits to Cisco that Kadabra murdered her partner, and she wants revenge. Barry wants to keep Kadabra locked up to try and get him to talk. He refuses. Joe agrees to let him out, but when Gypsy tries to stop him, he manages to get away. In the chaos, Caitlin is hurt. She needs surgery to remove shrapnel, but she can't go to the hospital because she'll be tagged as a meta.
She stays awake and walks Julian through the procedure. Cisco suggests removing her necklace so her powers can heal her, but Caitlin says she'd rather die. Julian performs the surgery successfully, and stays by her bedside. When Caitlin wakes up, he tells her how brave she was, and they kiss. He's forgiven her.
Gypsy reluctantly agrees to work with Team Flash to stop Kadabra once they realize he's stealing things to build a time machine. Barry, Wally, Gypsy, and Cisco tag team him while Joe and Iris guide them from STAR labs. They capture Kadabra. Barry makes one final plea for the truth, but he's not interested. He hates Barry too much. Gypsy takes him back to Earth-19.
Joe tells Iris that he doesn't know how to save her. But Barry has a new plan. He wants to put them on even footing with the villains by going to the future to get information.
Back at STAR labs, H.R. returns after missing all the action. He's been with a lady friend for two days. Caitlin teases Cisco about being worried about him. She begins to have a seizure. Julian rushes in and they attempt to revive her. But it's too late. At the last second, Julian yanks her necklace off, even as Cisco reminds him that's not what she wanted. Julian refuses to let her die. Caitlin's meta powers heal her, but when she wakes up, she's in full Killer Frost mode.