The fate of a thousand people lies on one woman's shoulders in the upcoming season finale of the hit Showtime series "Homeland."

In the promo released for episode 12 of the political-thriller drama, Carrie Mathison (Claire Danes) is seen running toward the train that could end many lives. After learning that the jihadists were planning to release the poisonous gas in the Berlin station, Carrie wasted no time, tracking down the culprits and stopping the inevitable. The clip shows her alone in the tunnel while holding her gun. The lights of the train are coming nearer as she shoots at it again and again. While it looks like her little gun is no match against the behemoth that is coming toward her, viewers should still not count her out of the equation, as the ex-CIA agent may end up accomplishing what many men will not be able to do.

Also in the teaser, Qasim (Alireza Bayram) is seen trying to kill Carrie. He is holding a steel pole to her throat while she is doing her best to fight him off. Carrie is telling Qasim that many people in both the platform and the station will perish if she will not be able to stop the train. Once it pushes the gas everywhere, even they can kiss their lives goodbye. Qasim appears to have not listened to her, as later on, the viewers will see her shooting him right when the train comes on view.

Meanwhile, journalist Laura Sutton (Sarah Sokolovic) can be heard saying she is convinced "he" is an important member of the terrorist group that planned the attack. While it remains unclear who she is referring to, several shots of the show's male characters are flashed on screen. These include Saul Berenson (Mandy Patinkin), Peter Quinn (Rupert Friend), Otto During (Sebastian Koch), and Numan (Atheer Adel). Speaking of Quinn, the clip shows him still unconscious. The doctor is stating that he just got out of surgery and that his hematoma is very large.

Elsewhere, Saul is still not resting until he captures Allison Carr (Miranda Otto).

"Homeland" season 5 finale airs Sunday at 9 p.m. EST on Showtime.