Fia is a little girl who always gets teased; Hampus is a little boy who always gets into trouble. One summer, the two find themselves to be kindred spirits, and begin to set each other difficult exploits; as each child succeeds he gains temporary possession of Fia's comforting round white stone. For their relationship, they assume new identities: Fia becomes Fideli and Hampus becomes Prince Perilous, a circus acrobat. Prince Perilous draws eyes, nose and mouth on the church tower clock; then Fideli goes without talking for a whole day, despite threats and pleas; Prince Perilous ties the circus elephant to the schoolteacher's flagpole; then Fideli plays ""The Nightingale"" on the piano in the cafe; Prince Perilous puts a hard boiled egg in the judge's bed, but when he attempts to retrieve it, he is intercepted. As the adult world closes in on them, the children retreat to their secret sanctuary inside a dense lime tree, and, determined to die together, eat poison mushrooms. The white stone falls, they are found, and the mushrooms are dismissed as harmless puffballs. On the first day of school, they are uneasy; neither wants his true identity to be revealed to the other. But the stone is exchanged once more, and the charm succeeds: Fia and Hampus are themselves, but, having been Fideli and Prince Perilous, they are no longer afraid. ""And from there on, I would have to tell about Fia and Hampus. But that is another story, of course."" The tongue-in-cheek humor is delightful when the children are performing their individual exploits, somewhat precious when the adults are acting out their separate drama. It's a curious story which combines a lively, inventive plot with symbolic overtones reminiscent of Penelope Farmer; its reception will be very much a matter of individual taste.