A nice romantic daydream of a story, about ""anonymous"" Billy who spends his summer days at a California beach on the edges of the crowd, though his mother wants him to get a job and save for college and his father would prefer that he be assembling a carburetor. Humiliated one day at volleyball, he goes off and, purposelessly at first, begins to build a sand castle that turns as the days go by to a preoccupation and attracts strangers' baffled admiration, threats from the Beach Patrol and the bikers up the shore, and, eventually, the interest of Sandy, the girl he had awkwardly and unsuccessfully pursued. This is more like a long short story than a novel, and in fact would be better even shorter, with the obligatory juvenile subtheme of accommodation to parents and future plans reduced. (What happens on the beach is success enough). But the ending, when Billy and Sandy at last bed down in one of the towers to the completed castle, and when the structure of sand that we knew wouldn't last is destroyed the next morning not by officials or bikers but by a huge wave from a quake off Hawaii, leaves an afterglow of fulfillment.