Near the end of the 23rd century, EnHaz officer superintendent Shan Frankland is just finishing a final case for her employer, the Federal European Union, on the Mars Orbital platform. She works in Environmental Hazard Enforcement -- the environment cops. In the future, genomes are patented, which means that private companies have a monopoly on the worlds' food supply. The earth is also dying because of the amount of pollution and waste in the environment. On her last day before retirement, she is paid a visit by Eugene Perrault, an FEU minister. She gives Shan a Sub-q, which is a carefully engineered injection designed to release information. The Suppressed Briefing she's been given will only reveal details to her conscious mind on a need-to-know basis; she has been briefed and she knows she accepted the mission with no qualms, but she just doesn't know why. She is then put into cryostasis, and embarks on a 150 year mission in the ISS Thetis. She was chosen to head up an interstellar mission to Cavanagh's Star, to investigate the mystery behind Constantine colony, which had left earth and then was never heard from again. 75 years later, Shan arrives at Cavanagh's Star along with a BBChan reporter named Eddie, a cadre of Royal Marines and an impatient group of scientists. However, the second that they enter orbit around Cavanagh's Star their ship is disabled, with every system knocked out except for minimal life support. It turns out that the colonists, all Quaker-style Christians, are alive and well. They have been taken care of (in all meanings of the phrase) by Aras, a member of the Wess'har species. The Wess'har are extremely environmentally conscious aliens, who take care of species that need help, and ensure the environmental balance of planets. The Wess'har are also taking care of one of the planet's indigenous life forms, the aquatic Bezeri, who were nearly wiped out by a third alien race, the Isenj. The Isenj had colonized this world before the Wess'har arrived, and, as mentioned, nearly made the Bezeri extinct by the pollution from their cities. The Isenj are now currently confined to the other habitable earth-like world in the Cavanagh system, and the edgy balance of power between the Isenj and the Wess'har is upset by the arrival of humans.