Fighting between Barry and Iris is a rare occurrence. Their communication has only gotten better since starting couples counseling, but that did not prepare them for the rift Nora has caused. A lot of hurtful words are thrown between them, and it’s revealed that Iris doesn’t think Nora’s actions are all together terrible. I’ve never seen Barry so hurt by someone he once idolized. The two separate in anger, with Iris going after Nora and Barry focusing his energy on finding Cicada.
With Ralph, Iris travels to the future to talk to Thawne and locate Nora. Desperate to return the past, Nora begs Thawne to show her how she can return without Barry knowing. He introduces her to the Negative Speed Force, but she doesn’t take to it at first. Always clumsy, it isn’t until she sees Iris and unleashes her anger does she connect to the Negative Speed Force and run to the past. Thawne looks concerned, afraid what door he opened in Nora. Iris notes this, and I feel her heart softens up to him as well. She later recalls to Barry she felt Thawne looked almost like a father. I still firmly believe Thawne has a plan for Nora and his concern is all an act.
In Central City, Barry’s attention is focused on the drama unfolding in Caitlin’s life. Icicle has returned to Tannhauser Lab’s to steal a device to replicate the conditions which caused Killer Frost to be born. Not only does he take the device, but he also kidnaps Caitlin and her mother, Dr. Tannhauser, for his experiment. While imprisoned, the two iron out their grievances, which opens them up to a more loving mother-daughter relationship.
Icicle’s experiment is to take a vial of Caitlin’s blood and use Dr. Tannhauser as a vessel for a new Meta similar to Killer Frost. Barry arrives on the scene to help save her, just after she’s injected. During the fight, Thomas emerges from Icicle as he gains control, but they’re not free just yet. Cicada appears, attacks Caitlin, and makes off with the same device. Thomas steps in to save Caitlin from Cicada’s dagger and is killed. She was so close to reconnecting to her family, and the opportunity just disappeared. She’s remained strong through every loss imaginable, and yet she’s still ready to fight Cicada.
While Cicada intends to use the device to wake her younger self, Nora connecting with the Negative Speed Force poses a more significant threat. With Barry and Iris are still at odds, Barry is going to have to calm down to reach Nora. Her anger and pain come from being rejected by him. A bit of an overreaction, but unless Barry handles it gracefully he’ll have another villain on his hands.