After a long and eventful life, Allan Karlsson ends up in a nursing home, believing it to be his last stop. The only problem is that he's still in good health, and in one day, he turns 100. A big celebration is in the works, but Allan really isn't interested (and he'd like a bit more control over his vodka consumption). So he decides to escape. He climbs out the window in his slippers and embarks on a hilarious and entirely unexpected journey, involving, among other surprises, a suitcase stuffed with cash, some unpleasant criminals, a friendly hot-dog stand operator, and an elephant.