The Host by Stephenie Meyer

In a future where humans bodies, “hosts”, are inhabitied by alien “souls”, the few remaining humans are rebels on the run. When Melanie Stryder is captured, the Soul named Wanderer is inserted into her body. But this insertion doesn’t go quite according to plan. You see, Melanie is not giving up so easily and has no intention to leave any time soon. Mel won’t let Wanderer access all of her memories and the few that slip past the stubborn wall have an interesting effect. Wanderer has lived many lives on other planets but has never had a human host. In a world with no hunger, no war, peace, community, and participation, this ninth life is teaching Wanderer about something she’s never encountered before, human emotion. Is it possible that in this life The Host could change the soul?