The answer to that question should offer an exciting bookend to what looks to be the biggest Arrowverse crossover event yet.
Crisis on Earth-X begins with Supergirl and Arrow on Monday, November 27 @8pm, and concludes with The Flash and Legends of Tomorrow on Tuesday, November 28 @8pm on The CW.
That means stars like Melissa Benoist are pulling double duty, playing not only Supergirl but also her evil inter-dimensional counterpart, Overgirl.
Crisis on Earth-X is coming to The CW’s Arrowverse this year and the crossover is not only offering some unsettling variations on familiar heroes, but the threat of a doomsday weapon as well.
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DCTV Crisis on Earth-X Crossover Promo #3 The Flash, Arrow, Supergirl, DC's Legends of Tomorrow (HD)