Zoom unleashes an army of Earth-2 meta-humans, the leader of which is Black Canary's doppelganger, Black Siren; Joe worries when Wally goes out to help The Flash.
Stars: Grant Gustin, Candice Patton, Danielle Panabaker
Director(s): Jesse Warn
Writer(s): Greg Berlanti, Andrew Kreisberg, Geoff Johns