With Crisis only two days away, Barry faces a crisis from within when Ramsey infects him with his black blood. Meanwhile, Iris, Allegra, and Kamila investigate the secret organization Ralph and Barry saw at the gala.

Flash, Killer Frost, and a newly repowered Vibe track down the Anti-Monitor's weapon of destruction and meet an electrifying new hero. Ray, Ralph, and Iris go to recruit the Paragon of Humanity, while Constantine helps Mia and Diggle recover Oliver's soul.