 In the early twenty-first century Earth is visited by the Taelons, an androgynous-looking alien species who call themselves the "Companions" and claim they wish to share knowledge with the rest of humanity in the hopes of getting to know us better. William Boone, a former Special Forces soldier turned cop, rescues Da an, the Taelon "overseer" for North America from assassination and is made the Companions  interspecies liaison. But Boone is really working for the human resistance who are trying to learn the Taelons  true motives, which may not be as generous as they claim.