Seven-year-old Lotte lives somewhere in Denmark with her mother Gudrun, her father Jørgen and her brother Øffe. When Øffe has to look after his little sister, Lotte notices that she suddenly becomes invisible when she presses on her ever-growing navel. Lotte soon finds out that Øffe can see her again when she presses her belly button one more time. Lotte decides to go to her mother's work for a day. But her mother doesn't know anything about it yet and the question is whether her invisibility navel will continue to work.