The Return picks up six years after the events of book 2 in the series, with John Wells leading another Mars mission. In the opening chapters, John discovers two things: first, there has been another manned Mars mission on the planet simultaneously with John's, launched by Rex Edwards's Delta-V Corporation as an advance colony. And second, he discovers the wreckage of a couple of the 'alien spiders' from the first books in the series.Meanwhile, people very close to John are living in captivity in Raines's complex in Slovenia. On Mars, the astronauts' Earth Return Vehicle, in orbit, is apparently hit by meteorites and ruined. They begin to move their entire base, on wheels, to the site of the colony. Kerry and the FBI monitor, through secret surveillance, Raines's compound in SloveniaIn preparation for impregnating the hundreds of teenage clone girls who first showed up in book 2, Raines moves them all to China; Monique escapes and stays behind, then plots with the FBI on how to apprehend and stop Raines. On Mars, John figures out who was behind everything.