A young girl called Annetje Lie is staying with her grandmother for an undisclosed period after her father unceremoniously dropped her off and left. At night, Annetje disappears into a dream world in which her friend the Moon transports her back to her elderly home. There she gets into all sorts of nightmarish adventures with the King of Mice and the mysterious Heintje Vaar. Meanwhile, her grandmother is beginning to suspect Annetje might be seriously ill.