Oskar is home alone for the weekend because his mother is attending a wedding. He immediately takes advantage of his freedom for an extensive shopping spree in the city. At a snack bar, he treats himself to an extra-large hamburger with the money his mother gave him. Shortly after, Oskar realizes that his wallet and his mother's gold bracelet are missing. Was it the strange boy at the snack bar who had acted so oddly? But how is he ever going to find him again? Oskar asks his classmates Fabio, Jessica, and Marina for help. They have little time, as Oskar needs to have his mother's bracelet back by Sunday evening at the latest.