According to Amazon.com, from Publishers Weekly, "In this tantalizing SF thriller, planet-hopping parasites are inserting their silvery centipede selves into human brains, curing cancer, eliminating war and turning Earth into paradise. But some people want Earth back, warts and all, especially Melanie Stryder, who refuses to surrender, even after being captured in Chicago and becoming a host for a soul called Wanderer. Melanie uses her surviving brain cells to persuade Wanderer to help search for her loved ones in the Arizona desert. When the pair find Melanie's brother and her boyfriend in a hidden rebel cell led by her uncle, Wanderer is at first hated. Once the rebels accept Wanderer, whom they dub Wanda, Wanda's whole perspective on humanity changes. While the straightforward narrative is short on detail about the invasion and its stunning aftermath, it shines with romantic intrigue, especially when a love triangle (or quadrangle?!) develops for Wanda/Melanie."