In a universe where humans and aliens coexist under the Earth Alliance, treaties dictate that humans must abide by alien laws when on their territory. 

However, these laws can be bewildering, with sanctioned murder and no sanctuary available, leading to punishments ranging from death to losing a first-born child. Enter the Retrieval Artists, a group of private detectives dedicated to aiding the 'Disappeared' in finding their way back home. [Adapted from the publisher]