Jack Connors and Sean Delaney, who've survived being hunted down by aliens, are living under assumed names in Mexico. They're finally getting over the events that sent them into hiding, but Jack is taunted by nightmares of his son, Nicky, calling out to him. Jack is traumatized as these episodes become more frequent, and he starts to worry that the secret government agency that was creating hybrid human-alien babies has found them. Sean tries to calm Jack, assuring him that he is just being paranoid and fearful. But then nightmares begin to haunt both men, and strange things start to happen. Can everything they're experiencing be a coincidence? Are they hallucinating? Or are they about to find out that monsters are real and lurking just around the corner?