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. <br /> <br />Director: Jesse Warn <br /> <br />Writers: Greg Berlanti (developed by), Andrew Kreisberg (developed by) <br /> <br />Stars: Grant Gustin, Candice Patton, Danielle Panabaker
