When Barry and Iris deal with the loss of their daughter, the team faces their greatest threat yet - one that threatens to destroy all of Central City; Killer Frost has a brush with death that will change her relationship with Caitlin.
Faced with the news of his impending death, Barry's resiliency suffers as he struggles to fight fate; 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; Ramsey Rosso uses his deadly new abilities to save his own life, while sacrificing his humanity in the process.
Barry turns his attention to prepping Elongated Man for life after Crisis and without The Flash, but Ralph ultimately teaches Barry a lesson. Meanwhile, Cecile faces her own moment of self-discovery while helping a recuperated Chester P. Runk reclaim his identity.
As Barry stands on the threshold of his impending death in Crisis, his convictions are tested when the monstrous Dr. Ramsey Rosso infects The Flash with a mysterious, hallucinogenic contagion. Meanwhile, Iris uncovers a vast conspiracy.
With The Flash freshly infected by the monstrous Bloodwork, Iris and Cisco battle to help Barry take control of himself before he's lost forever to Ramsey's influence. Meanwhile, the rest of Team Flash fight to reclaim control of Central City from Bloodwork's growing army.