The real sand castle which Alec starts to build at the beach is taken over by his mother, father, aunt, and uncle, so that there is nothing left for Alec but to imagine one of his own. ""Why don't you come and watch us?"" his mother calls with typical parental insensitivity. ""Mustn't daydream all the time, dear."" But when rain washes away the grown-ups castle (""Well, if that isn't a rotten break! Sorry, Allie,"" says father), Alec still had his castle, ""for keeps."" Stevenson's New Yorkerish adults make a proper foil for the good-natured irony, and there must be lots of Alecs who'll nod in recognition.