A parasitic alien soul is injected into the body of Melanie Stryder (Saoirse Ronan). Instead of carrying out her race's mission of taking over the Earth, "Wanda" (as she comes to be called) forms a bond with her host and sets out to aid other free humans. Based on the novel of the same name by Stephenie Meyer, this sci-fi thriller also stars Max Irons, Diane Kruger, Jake Abel & William Hurt.