War. Plague. Famine. Death. The metaphorical horsemen had a field day with humanity, driving civilization to ruin before we could even make it to the next century. The post-apocalyptic society of Pan now survives by growing rice and scavenging among the wreckage of their destroyed civilization. But their precarious existence comes under threat when the powerful, technologically advanced Federation of Fortuna forces them into a dangerous choice—submit to Fortuna’s rule or best them in a barbaric, ritualized game known as “Celestial Mechanics”. Pan’s only hope? A hot-headed outcast they’d rejected for being too “un-Pan”: a girl named Aster.