 Deputy Jake Hannah, a good guy who does well as substitute big brother for Corrine s young son Campbell Maguire, was already having another bad day in his private life, with his girl friend, the sheriff s daughter, telling she has enough of him failing to set a wedding date, when he is called in on duty because the only notable installation in his small West-Tennessee town, the nuclear plant, is hit by a small tornado; it s Saturday, so there s only a skeleton crew headed by supervisor Corrine Maguire, which despite good intentions causes dangerous mistakes. Things get much worst fast because two more twisters appear, ravaging even strong buildings in the whole area. Jake is bravely searching and rescuing people, including Campbell, while in the plant the cooling system goes down and contact with the experts is broken off...