One moment Carrie Williams is eight-and-a-half months pregnant and driving to meet her husband Robbie. The next a silver streak rushes into her car's path. Carrie tries to turn the wheel, resulting in a horrific accident. It is in Carrie's dying moments that she sees the alien, whose vehicle almost collided with hers. The alien senses the small life form in Carrie's body and merges her form with that dying human body to save a life, unaware how that single choice will change everything for lives in both races.