When Earth is attacked by a new race of aliens, they find themselves not harmed but simply taken over by them. When those, who are known as Seekers, find Melanie and put a Waderer into her, she tries to convince it not to tell anything to the Seekers. The only thing the Seekers want is to find every one of the humans and turn them into their hosts, all of them. But, they can't seem to get their hands on a group of humans that are hiding under the ground in front of their noses. As Melanie escapes, and heads back to the hidden place, their own people don't trust her and avoid her. She must now earn their trust again and help them defeat one of the Seekers. The main role in this action sci-fi with romance elements plays talented Saoirse Ronan, who brings her main character, Melanie as well as her alien character, Wonda, to life. Her fellow actors make the whole package great and really captivating. The director of this movie is Andrew Niccol. Since March 2013, when the movie was released, millions of people got amused by it and held on pins and needles for the whole time as the movie lasts.