After the colonization of Mars and Europa, it took us fewer than five generations to reach beyond our solar system and discover new planets capable of supporting human life. Too far away to be governed under Earth law, the Collective was formed. Several hundred years later, the Collective has expanded to a thriving system of six inhabited worlds. Old captain Aramis Reyne and his ragtag crew on the Gryphon are runners, part of the Collective's interplanetary postal service. They deliver mail and supplies to the farthest, darkest reaches of the system known as the fringe. After a warship captain confiscates one of his packages, Reyne discovers a galactic conspiracy involving military leaders, secret organizations, fringe rebels, and pirates…with the Gryphon’s crew stuck in the middle. The only way out is for Reyne to make an impossible delivery, and the entire Collective is at stake if he fails.