Ronan will play Melanie Stryder, one of the last humans putting up a fight against an alien species called Souls. These parasites invade human bodies, fuse to each person’s consciousness and systematically erase their personalities.
Melanie is captured by the aliens and implanted by a Soul called Wanderer, something of a legend because of all of the “hosts” she has attached to on numerous planets. Wanderer’s goal is to get Melanie to give up the remaining pockets of humans, but instead the alien finds Melanie to be unique in her unwillingness to surrender her consciousness.
Wanderer is so overwhelmed by Melanie’s memories and feelings, the alien is driven to reconnect with Melanie’s old life.
Twilight Saga Writer’s New Movie To Star Saoirse Ronan (Deadline)