After nearly dying on the surface, Chell returns to Aperture. She reluctantly places her trust in GLaDOS, but GLaDOS is playing the long game. ChellDOS, slow-burn.
A short exploration into Doug's reasons for painting.
After Caroline discovers her 'parents' to be Black Mesa spies, Doug Rattmann hides young Chell in Old Aperture before she's sealed off and presumed dead. Years later, she's back, and her resurfacing could lead to Aperture's downfall.
Sometimes you just need someone to hold you and tell you everything's going to be okay.
During the slow transfer back into her chassis, GLaDOS reflects upon her time spent as a potato and the injured test subject in her chamber. Inspired by a line from "PotatOS Lament."