The unemployed Cindy Campbell is hired to work in a cursed house as caretaker of an old lady and meets the ghost of a boy. Meanwhile, the teenager son Robbie and the young daughter Rachel of his next door neighbor and crane operator Tom Ryan are spending the weekend with their loser father. Cindy and Tom meet and fall in love for each other, but when Giant Tripods invade Earth, Tom escapes with Robbie and Rachel; Cindy travels to a village, trying to find the answer to a riddle to save the world; and the president of USA organizes the defense of the planet in UN under his intelligence and leadership.