In the generator room, Shirly and Walker hear Juliette’s voice come through the rebuilt radio, calling for Solo. Because the voice is unmistakable and comes from equipment Walker has only just assembled, Walker realizes the signal is live rather than some lingering echo from the past. That conclusion means Juliette survived cleaning and also confirms that there are other silos and other people beyond Silo 18.

The discovery transforms both of them. Walker shifts from fearful disbelief to excitement, and Shirly begins to imagine Juliette alive somewhere outside the world she thought was fixed and closed. When Shirly asks whether they can answer, Walker realizes they are missing a transmitter board; he explains that the headphones’ microphone cannot send on its own, but that a blasting-cap transmitter from the mining storehouse could work.

Shirly volunteers to fetch the part while Walker stays with the radio and keeps listening for Juliette. Outside, she sees frightened onlookers and briefly wants to announce the news, but urgency stops her. Jenkins intercepts her and tells her the rebels are about to blow the stairwell to trap or kill advancing enemies. Shirly insists the errand is for the radio, and Jenkins grudgingly gives her only a few minutes before the attack proceeds.

Shirly runs to the mining levels, passing armed workers and thinking that the civil war now feels absurd compared with the revelation that escape and other communities may exist. In the storehouse she searches frantically, finally breaking open a locked drawer in the foreman’s office and finding transmitters, relays, and some dynamite. She races back just as the charges are triggered; the stairwell explodes, she is thrown to the floor, and gunfire erupts. Even amid the blast and the wounded screaming, Shirly ignores the battle and hurries back to Walker with the transmitter, focused on answering Juliette.