“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Luke Macfarlane and Melissa Benoist Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Melissa Benoist and Luke Macfarlane Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Melissa Benoist and Luke Macfarlane Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Luke Macfarlane and Melissa Benoist Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City. Also, Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford, pictured), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City. Also, Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford, pictured), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Charles Halford and David Harewood Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: Charles Halford, David Harewood and Chyler Leigh Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City. Also, Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford, pictured), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Alex’s (Chyler Leigh, pictured) mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

“Human For a Day” — Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (8:00-9:00 PM, ET/PT) on the CBS Television Network. Pictured left to right: David Harewood and Chyler Leigh Photo: Darren Michaels/Warner Bros. Entertainment Inc. © 2015 WBEI. All rights reserved.

Official Synopsis:

“Human For a Day” – Kara and her friends must rely on their inner strength and courage when an earthquake strikes National City. Also, Alex’s mistrust of Hank reaches a breaking point when the earthquake traps them in the DEO with Jemm (Charles Halford), a powerful alien escapee, on SUPERGIRL, Monday, Dec. 7 (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: Laura Benanti as Alura/Astra, Peter Facinelli as Maxwell Lord, Luke Macfarlane as Agent Donovan.

Guest stars: Charles Halford as Jemm, Ashton Bingham as Senior Tech, David Lim as Agent Tsung, Ayo Sorrells as Agent Reynolds, Stephanie Arcila as Woman, Zhuair Haddad as Store Owner, Casey Strand as Reporter, Bryan Lugo as Looter.

“Human For a Day” was written by Yahlin Chang and Ted Sullivan. Directed by Larry Teng.

‘Supergirl’ Season 1, Episode 7 “Human For a Day” airs Monday, December 7th at 8:00-9:00 PM, ET/PT.