Transcendence

The U.S. government tracks an unknown object entering our system and then landing on earth. Things get dicey when they realize an unknown entity has taken an interest in an unsuspecting person living there and turns his live upside down. When the entity finally reveals itself and explains why it came and what it is looking for will things remain the same as they were for the unsuspecting man and will the government let the entity complete its mission or simply try to stop it even if it was friendly?