Next week's "Flash" episode will feature some familiar faces -- and they might not exactly be friendly faces where Barry Allen is concerned. "Invincible" will see the debut of Laurel Lance's (Katie Cassidy) Earth-2 counterpart, the villain Black Siren. New photos released by the CW reveal that Black Siren won't be working alone, either; she's shown standing side by side with Reverb and Killer Frost -- the evil counterparts of Cisco Ramon and Caitlin Snow. There's just one catch: both Reverb and Killer Frost are dead. Have they been resurrected? Is this a flashback? Or are Cisco and Caitlin going deep undercover? We'll have to wait until Tuesday, May 17th to find out.

KATIE CASSIDY GUEST STARS AS 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. Jesse Warn directed the episode with story by Greg Berlanti & Andrew Kreisberg and teleplay by Brooke Roberts & David Kob (#222). Original airdate 5/17/2016.

"The Flash" airs on Tuesdays at 8 PM ET on the CW.