The Host is a 2013 American romantic science fiction thriller film adapted from Stephenie Meyers novel of the same name. It tells the story of a young woman, Melanie, who is captured after the human race has been taken over by parasitic aliens called Souls. After Melanie is infused with a soul called Wanderer, Melanie and the alien Soul vie for control of her body. Written and directed by Andrew Niccol, the film stars Saoirse Ronan, Max Irons, Jake Abel, William Hurt, and Diane Kruger. Released in theaters on March 29, 2013, the film was poorly received by critics.
A human on the run named Melanie Stryder is captured and infused with a soul called Wanderer. Wanderer is asked by Seeker to access Melanies memories in order to discover the location of a pocket of unassimilated humans. Surprisingly, Melanies consciousness has not been eliminated, and it struggles for control of her body. Melanie and Wanderer carry out an internal conversation and debate with each other, forming something of a friendship.Wanderer shares with Seeker that Melanie was traveling with her brother, Jamie, and her boyfriend, Jared Howe, to find Melanies uncle Jeb in the desert. Wanderer admits that Melanie is still present, so Seeker decides to be transferred into Melanies body to get the information herself. With the help of Melanie, Wanderer escapes and makes her way to the desert, where she is found by Jeb, who takes her to a series of caves hidden inside a mountain where the humans including Jared and Jamie are hiding. ........
Source: Wikipedia