While Barry and Iris deal with the heartbreaking loss of their daughter, Nora, the team faces their greatest threat yet — one that threatens to destroy all of Central City. Meanwhile, Killer Frost has a brush with death that results in an unexpected new dynamic that will change her relationship with Caitlin forever.

Faced with the news of his impending death, Barry’s resiliency suffers as he struggles to fight fate. Meanwhile, Cecile’s career as a D.A. conflicts with her identity when she crosses paths with a villainous meta-human.

Barry’s efforts to prepare Cisco for Crisis are derailed when Cisco schemes to save Barry’s life instead. Meanwhile, Ramsey Rosso uses his deadly new abilities to save his own life, while sacrificing his humanity in the process.