Trouble begins when siblings Valdemar and Sille are home alone and Valdemar crashes his dad´s brand new car. The next day he meets physicist Benedict who lurks Valdemar to test the time machine he has invented. Suddenly, Valdemar finds himself in the year 963, the time of Vikings in Denmark, where he learns that Benedict has become immortal after being enchanted by a witch. But eternal life is deprived of friends and love, and Benedict's only wish is to live a normal life. To earn money for the car repairs, Valdemar and Sille travel back in time to unearth a cross that can lift the curse.