Jojje, Roffe, Sivert, Lillen, Peggy and the dog King are a tight-knit group of friends. When it turns out that King is sick and soon to die, his friends decide to give him his best time.
The ten year old Nisse suffers from acute asthma and is rushed to the hospital. There he meets Lelle who is a bitter, lonely and seriously ill twelve-year-old. Lelle, who never gets any visits treats Nisse kindly. Lelle inaugurates Nisse in his secret plan to build a giant Zeppelin and steal the food available in the hospital's underground reserves.
