Beacon 23 takes place in the farthest reaches of the Milky Way and follows Aster (Lena Headey), a government agent, and Halan (Stephan James), a stoic ex-military man, whose fates become entangled after they find themselves trapped together inside one of many Beacons that serve as a lighthouse for intergalactic travelers. Every Beacon is run by one highly trained human and a specialized Artificial Intelligence. Aster mysteriously finds her way to the lonely Beacon-keeper Halan, and a tense battle of wills unfolds. Halan begins to question whether Aster is friend or foe, as her ability to disguise her agenda and motives could make her a formidable opponent.