“Better Angels” — Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

CBS have released a promo and new stills from the upcoming season 1 finale of ‘Supergirl,’ titled “Better Angels.”

“Better Angels” — Supergirl (Melissa Benoist, left) 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. Also pictured: Chyler Leigh (right) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, right) 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. Also pictured: David Harewood (left) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“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. Pictured left to right: Peter Facinelli, Chyler Leigh, Melissa Benoist and Helen Slater Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“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. Pictured left to right: Melissa Benoist, Helen Slater and Chyler Leigh Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, left) 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. Also pictured: Peter Facinelli (right) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, right) 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. Also pictured: Mehcad Brooks (left) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, left) 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. Also pictured: Mehcad Brooks (right) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, right) 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. Also pictured: Jeremy Jordan (left) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“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. Pictured left to right: Jeremy Jordan, David Harewood, Helen Slater, Chyler Leigh, Melissa Benoist and Mehcad Brooks Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“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. Pictured left to right: David Harewood, Helen Slater, Chyler Leigh, Jeremy Jordan, Mehcad Brooks and Melissa Benoist Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“Better Angels” — Supergirl (Melissa Benoist, left) 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. Also pictured: Mehcad Brooks (right) Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

“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. Pictured left to right: Mehcad Brooks, Melissa Benoist, Jeremy Jordan, Chyler Leigh and David Harewood Photo: Cliff Lipson/CBS ©2016 CBS Broadcasting, Inc. All Rights Reserved

Official Synopsis:

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.

Stars: Melissa Benoist as Kara Danvers/Supergirl, Calista Flockhart as Cat Grant, Chyler Leigh as Alex Danvers, Mehcad Brooks as James Olsen, David Harewood as Hank Henshaw and Jeremy Jordan as Winslow “Winn” Schott.

Recurring Cast: Jenna Dewan-Tatum as Lucy Lane, Chris Vance as Non, Peter Facinelli as Maxwell Lord, Laura Vandervoort as Indigo, Briana Vensku as Agent Vasquez, Glenn Morshower as General Sam Lane, Dr. Eliza Danvers as Helen Slater, Kitana Turnbull as Costumed Girl, Dan Warner as Fire Captain, Malina Weissman as Young Kara.

Guest stars: Dawn Greenidge as Pedestrian Woman, Jessica Garcia as Teenage Girl.

Story by Andrew Kreisberg and Ali Adler. Teleplay by Robert Rovner and Jessica Queller. Directed by Larry Teng.

‘Supergirl’ Season 1, Episode 20 “Better Angels” airs Monday, April 18th at 8:00-9:00 PM, ET/PT.