Check out 'The Flash' Season 2 episode 22 promo and synopsis: Laurel returns as Black Siren, Zoom's ally

"The Flash" Season 2 is coming to an end, with just two more episodes left, and hopefully our hero will defeat Zoom (Teddy Sears) before the finale. In the upcoming episode, Laurel Lance (Katie Cassidy), who most fans will know as Laurel Lance aka Black Canary of "Arrow," will come to Central City as Zoom's ally Black Siren from Earth 2, and it is anyone's guess what ruckus she will cause.

The promo and synopsis for the upcoming Season 2 episode 22 titled "Invincible" has been released, and it is clear that Zoom's evil plans for Earth-1 are far from over. He is unleashing an army of meta-humans from Earth-2 led by Black Siren on Central City.

Black Siren is the Earth-2 doppleganger of Black Canary, who was a superhero and Team Arrow member from Star City. Black Canary, however, died at the hands of the villainous Damien Darhk (Neal McDonough) recently. She did not have any superhuman powers, unlike her meta-human counterpart.

It remains to be seen if Black Siren will be a recurring character or a guest star. If Team Flash can get through to her, she can hopefully become a member of the superhero team and put her powers to good use on Earth-1.

Check out the synopsis for Season 2 episode 22 of "The Flash" here:

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.