The CW has released stills from next Tuesday’s « Invincible » episode of The Flash, and they offer the first official images of former Arrow star Katie Cassidy as Black Canary’s Earth-2 counterpart, Black Siren.
After Zoom (guest star Teddy Sears) unleashes an army of Earth-2 meta-humans on Central City, Barry (Grant Gustin) is shaken when he sees their leader is the Black Canary’s Earth-2 doppelganger, the Black Siren (guest star Katie Cassidy). Meanwhile, Wally (Keiynan Lonsdale) takes to the streets to help The Flash stop the meta-humans, which worries Joe (Jesse L. Martin). Iris (Candice Patton) and Henry (guest star John Wesley Shipp) are concerned about Barry taking on Zoom.
Source : Arrow’s Katie Cassidy Comes To The Flash In New Invincible Photos