The generator room is packed with silent mechanics as Juliette oversees the final alignment of the rebuilt generator and dynamo. Using a device she made from mirrors and slits of light, Juliette tries to line up the machinery with extreme precision. Four days into the power holiday, Juliette feels intense pressure because the refit was her idea, the generator has never been fully shut down in most living memory, and the silo needs the system running again by morning.

After Marck confirms the last bolts and lock nuts are secure, Juliette joins Marck and Shirly in the control room. Shirly reports that the controls have been reset and stripped of old compensations so they can judge the rebuilt machine cleanly. As the crew waits, Juliette reflects that this may be the last major repair job of her life in Mechanical before she leaves for her new role up top, a change that frightens her more than the restart itself.

Juliette engages the starter motor, and the loud whine drags on long enough to worry everyone. Marck opens the door to listen for any call to abort, and someone outside signals frantically to stop. Before Juliette hits the kill switch, she realizes the rebuilt generator is already running: the machine is so smooth and quiet that the crew mistakes the starter motor for the only sound. The successful restart proves the refit worked and releases the tension that has built over days of exhausting labor.

With the gauges looking good and the generator humming cleanly, the mechanics erupt in cheers and crowd around the machine with awe. Juliette watches the celebration and feels new confidence about facing the future above, encouraged by the visible success of her work. Then a young porter rushes in, pale and breathless, and grim news spreads across the room from person to person. The celebration collapses into sobs and stunned silence, and Juliette understands that something major and terrible has happened elsewhere in the silo.