Friendly parasites have descended upon planet Earth to invade the bodies of human beings. Their mission? To spread peace, health and harmony. Indeed — this is the premise of Stephenie Meyers' first novel for adults, The Host, and the premise is a good one. Humans are quickly outnumbered as aliens commandeer the planet, abolishing war and curing cancer. The parasites are "all things good: compassionate, patient, honest, virtuous, and full of love." It's a weird, weird, world.

"Wanderer" is the name of an alien soul inserted into the body of a human host named Melanie Stryder. Only problem is, unlike the other humans, Melanie's spirit won't let go — her human consciousness persists even after her body is no longer hers. Wanderer and Melanie, trapped in the same form, wind up on an odyssey in search of Melanie's family, who maintain a rebel holdout in the Arizona desert. The subtlety of Meyers' book will come as a pleasant surprise to those readers skeptical of the Twilight phenomenon, for which the author is also responsible. The Host is fresh, briskly paced and brimming with the kinds of imaginative details that make (or, in their absence, break) a sci-fi thriller.