Two thieves on the run visit Pippi to steal her gold-coins, but when she tells them that Mr. Nilsson is sleeping in the other room, they get frightened and run away, not knowing that Mr. Nilsson is only a small monkey. In the evening Pippi has invited Tommy and Annika to her birthday-party. She takes them to the attic, to see if they can find any ghosts. In the night the thieves come back, but they cannot overpower Pippi, the strongest girl in the world.