In a future where all plant life on Earth has perished, Valley Forge, one of a fleet of American Airlines space freighters, preserves the last remaining botanical specimens in vast geodesic domes as it orbits Saturn. Freeman Lowell, a passionate botanist, tends to these precious ecosystems, striving to maintain a semblance of the natural world. When orders come from Earth to destroy the domes and return the freighters to commercial service, Lowell rebels, driven by his dedication to ecology and conservation. He envisions a world where plants and animals can thrive once again, and he’s prepared to fight for that future.

Lowell commandeers Valley Forge, severing ties with Earth and his crewmates who do not share his environmental convictions. The narrative centers on Lowell’s solitary struggle to uphold his ideals in the face of isolation and the operational demands of the ship. Assisted by a trio of small, drone-like service robots he reprograms for companionship and help, Lowell embarks on a lonely vigil, tending his green charges amidst the stars. The film becomes a contemplation of sustainability, stewardship, and personal responsibility, posing profound questions about humanity's relationship with nature and the cost of progress.