CBS has released the official synopsis and first photo for the season finale of "Supergirl."

Titled "Better Angels," the episode features Kara's "greatest test yet" as she takes on Non, Indigo and an "unexpected foe."

The "Supergirl" season finale airs Monday, April 18 at 8 p.m. on CBS.


SUPERGIRL FACES HER GREATEST TEST YET WHEN HER ENEMIES PLAN TO DESTROY EVERY PERSON ON THE PLANET, ON THE FIRST SEASON FINALE OF "SUPERGIRL," MONDAY, APRIL 18

"Better Angels" - Supergirl is forced to do battle with an unexpected foe and must risk everything - including her life - to prevent Non and Indigo from destroying every person on the planet, on the first season finale of SUPERGIRL, Monday, April 18 (8:00-9:00 PM, ET/PT) on the CBS Television Network.