After a series of reckless incidents leading to his partner's tragic death, the impulsive cop Brian Nightraider is ousted from the police force. Amid his despair, an intriguing offer from the United Nations Immigration Bureau's Special Investigation Unit comes his way. Tasked with managing Borderlanders, a covert group of human-like aliens, Brian is recruited into the Marginal Service, a clandestine division of the UN. These Borderlanders live among humans peacefully, but a new threat emerges as a terrorist faction starts peddling a powerful substance known as Confu. With their unique abilities to regenerate and blend seamlessly, uncovering the drug ring poses a formidable challenge. Yet, the eclectic team at the Marginal Service stands undaunted, even as their investigations unveil some unexpected truths about those around them.