In a dystopian future, the Earth's atmosphere has been rendered toxic, and humanity's survival depends on a few select individuals who are placed in cryogenic sleep. These individuals are responsible for maintaining underground bunkers where the remnants of civilization are kept in stasis. The story centers on two engineers, Bauer and Cartwright, who are tasked with performing routine maintenance in one such facility. They awaken for a limited period every six months to ensure the life support systems remain functional. As they follow their stringent protocols in the claustrophobic environment, they confront the psychological strains of isolation and the immense responsibility of their mission.

As Bauer and Cartwright carry out their duties, their fragile mental states become increasingly apparent. The confined space and lack of interaction with the outside world amplify their anxieties. During one of their cycles, a critical malfunction threatens the stability of the bunker, putting both their lives and the future of humanity at risk. Tensions escalate as they struggle to solve the problem while contending with their growing distrust of each other. The boundaries between reality and paranoia blur, leading them to question their perceptions and decisions. As they delve deeper into the malfunctions, they uncover unsettling truths that challenge their understanding of their mission and each other.