[s4e8] Crisis On Earth-x, Part 3 -

"Crisis on Earth-X, Part 3" is the third installment of the 2017 Arrowverse crossover, airing as The Flash season four, episode eight. The plot follows the captured heroes in a Nazi-dominated Earth-X reality, featuring the introduction of The Ray and Citizen Cold, while on Earth-1, Iris West and Felicity Smoak fight to retake S.T.A.R. Labs from evil doppelgängers. For a detailed episode guide, visit Arrowverse Wiki .