Three years after Allison went outside, Holston reflects on how grief and doubt changed him. During the first year after Allison's death, Holston waited for her to return, half-believing her claims that the silo hid the truth. During the second year, Holston nearly asked to go out himself but lost his nerve. By the third year, after studying Allison's recovered files and becoming convinced that his world was built on lies, Holston finally follows her path.

Sealed in the airlock in a cleaning suit, Holston endures the final procedures as argon fills the chamber and the outer doors open. He slips through the gap expecting only a brief, fatal glimpse of a dead world. Instead, after climbing the ramp to the surface, Holston is overwhelmed by a vivid landscape of green hills, blue sky, white clouds, and signs of life. The beauty shocks him into realizing that the dead, grey world shown inside the silo is false.

Remembering Allison's last moments, Holston suddenly understands why cleaners always perform the cleaning even when they swear they will not. He approaches the silo's exterior cameras and wipes them, not from anger but from pity and joy, wanting the people inside to see what he now sees. As he cleans, he concludes that the grime is real but the ruined landscape shown on the silo screens is an artificial overlay, matching Allison's discovery of image-altering programs.

While methodically cleaning each lens, Holston tries to reason through the deception. He wonders whether anyone in the silo knowingly maintains the false image, whether the lie survives from before the uprisings without current understanding, or whether the illusion was created to stop people from wanting to leave. The revelation reframes Allison's beliefs, the silo's history, and the meaning of every past cleaning.

After finishing the final camera, Holston thinks about Allison and the possibility that she is still somewhere beyond the hill. He briefly wants to tear off his suit and run toward the distant city, which now appears whole and larger than he ever knew, but instead follows the ritual established by earlier cleaners. Accepting that he has joined their hidden knowledge, Holston turns away from the silo and walks toward the dark path over the hill, convinced that even familiar details of the barren outside had been fabricated.