The Supernaturalist by Eoin Colfer Around fifty years into the future, Satellite City is not a part of any welfare state. Children without sponsors are sent to institutions which have to pay their own ways. Clarrisa Frayne Institute for Parentally Challanged Boys uses its charges for product testing. The average life span of the boys is fifteen years. Cosmo Hill escapes when the satellite goes on the blink. As he lies in pain, a blue creature lands on his chest, and he feels the pain beginning to fade. A motley crew(somebody give me a better phrase) comes along and zaps the blue creature, and then heals Cosmo's wounds. The group calls itself the Supernaturalists, because they can see the blue things, which they call parasites, and most people can't. The parasites are seen only by a fraction of people who have near death experiences. The Supernaturalists are dedicated to killing all of the parasites, and Cosmo joins them. Then the Supernaturalists experience a paradigm shift as they find out that the parasites are not what they seem.
The Supernaturalist is easily the most mature of the Colfer books I've read (check the index to see which those are). The terror of this story still never seems quite real, and the comedy moves the story. The evil of corporations is presented; the book jacket's description of Cosmos's world as a futuristic Dickins is apt.
Happy reading.