After discovering Reggie Davis escaped through the window, Anna immediately follows him outside, deciding the roof is the only place she can track his movements and prevent him from reaching Dante, Sal, and Jack Lapsford. She removes her shoes, squeezes through the window, and faces brutal wind, snow, and cold that make every movement perilous as the train barrels toward Chicago.

Anna carefully climbs from the window to the roof, contending with vibration, ice, and slick metal ridges. Despite the danger, she hauls herself to the center of the roof and forces herself upright, aware that a single misstep could send her tumbling from the train.

Through the blowing snow, Anna spots Reggie two cars ahead on the first-class lounge. She draws Reggie’s revolver and shouts for him to stop, but she refuses to shoot him because she wants him to face a prolonged reckoning rather than an instant death. Knowing this, Reggie advances, moving from car to car as Anna retreats to maintain distance.

As they near Chicago’s outskirts, Reggie presses Anna to drop the gun or join his campaign of vengeance, insisting their victims “had it coming” and even implicating innocent Dante Wentworth because of his family. Anna rejects him and keeps backing away, only to realize she has been driven onto the last car—the observation car—with no escape behind her.

Reggie closes to within arm’s length on the observation car roof until the gun is against his chest. When he demands she admit she will not shoot him on the roof, Anna pivots the plan: she confirms she will not shoot him “up here,” but “down there.” Standing over the observation car’s roof window, Anna lowers the revolver and fires a shot through the skylight glass beneath them.