The Host 2013

Melanie (Saoirse Ronan), one of a small band of human resistance, is caught by The Seeker (Diane Kruger), a peace-keeper responsible for defending this new race from the last of the humans. After a desperate struggle, a Soul named Wanderer is surgically implanted into Melanie's body.

Wanderer is warned about the challenges of living inside a human; the overwhelming emotions, passions, the too-vivid memories, but there is one difficulty that she didn't expect: the former tenant of her body refusing to relinquish possession of her mind.