Some years ago, the cadets of the 104th Cadet Corps complete a snowstorm training exercise, arriving at a base at the foot of a mountain. After some brief discussion among the cadets, Reiner announces that Christa is missing. Mikasa says that Christa had chosen to stick with Daz, who was performing poorly, but Reiner says that Daz as well as Ymir have not returned. Marco suggests that she may be with Thomas' squad, but Reiner points out that his squad just completed their course with Ymir, Daz, and Christa nowhere in sight. Worrying for their safety, Eren proposes organizing a search for them, and their training instructor says that a search will begin the next morning. Eren insists that it will be too late if they hold off on the search, but the instructor says that more cadet lives cannot be risked in the snowstorm.
Elsewhere in the storm, Christa and Ymir make their way through a forest with Daz unconscious in a cot pulled by Christa. Ymir says that they will only survive if they abandon Daz and head for base together, but Christa insists that they can all survive if Ymir goes ahead alone while Christa takes Daz. Ymir notices that Christa has not asked for help during their entire course, and she realizes that Christa has no intention of saving Daz nor herself. She says that it would be very against Christa's character to bring about Daz's death while searching for her own heroic end, but Christa insists that such is not the case
Ymir leads Christa to a cliff overlooking the base at the foot of the mountain and proposes tossing Daz over the edge so that she and Christa can make it to base alive while Daz can be searched for later. When Christa objects, Ymir takes matters into her own hands and throws her aside into a snowbank. Ymir wanders off while Christa is submerged, and there is a flash of light in the distance. When Christa escapes from the snow and returns to the cliff, Ymir and Daz are nowhere to be found. Back at base, Eren prepares to head outside in search for the others, and Mikasa and Armin decide to help. Reiner and Bertholdt also decide to join, bringing more equipment for the trip. Conny, Marco, and Sasha agree to come along as well. Suddenly, a loud crash like thunder is heard outside, and the cadets head outdoors to investigate. In the distance, Sasha spots Ymir dragging Daz through the snow. Some time later, Christa arrives and spots Ymir outside the base. She asks about Daz, and Ymir shows her that Daz is safe indoors. Upon looking at the cliff from the ground, Christa sees that such a descent would be impossible without rope. Ymir decides to reveal to Christa how she saved Daz, but only if she promises to live by her true name when her secret eventually becomes known to everyone.