Sitting quietly in his room at the old people's home Allan Karlsson is waiting for a party to begin. His one-hundredth birthday party. Everyone will be there, Allan however will not. Escaping in his slippers, through the bedroom window, Allan makes his getaway. And so his journey begins involving a suitcase full of cash, a few thugs, a very friendly hot-dog stand operator, a few deaths, an elephant and incompetent police. As his journey unfolds, Allan's earlier life is revealed, a life in which he remarkably played key roles behind the scenes in some of the momentous events of the twentieth century.