Five strangers bound by concrete and dread hole up beneath a scorched America, waiting for radiation to thin enough to breathe. Food vanishes. Medicine runs dry. Nerves fray into territory no bunker was designed to contain. The youngest among them, restless and half-feral with need, makes a decision that nobody else has the courage to face. Above, the world is poison. Below, so is everything they've become to each other. The shelter stops being a refuge almost immediately, turning instead into a slow-burning pressure cooker of want, boredom, and bodies too close together for too long.