The Ring of Charon is a science fiction book by American writer Roger MacBride Allen, first published in 1990 by Tor Books. It is the first in a series of three (although the third book has yet to be published) books under the name of The Hunted Earth.The story unfolds as an unknown alien race captures Earth with the use of a controlled wormhole, which was triggered accidentally by artificial gravity experiments issued from a human outpost in space. The story follows all three viewpoints: the Earth, the Solar System (sans Earth) and the alien race (Charonians). Source: Wikipedia (en)