The trouble with those celebrity-studded sagas that litter the best-seller list is that nobody really leads the kind of life that intersects so fortuitously with the fated and famous. Do they? Do we simply have a span of days, or do we have destinies?

Because I thought I knew the answers to such questions I was properly skeptical when I picked up "Twelve Years" by Joel Agee. Consider this: The son of the novelist and screenwriter James Agee emigrates to East Germany with his mother and stepfather (who is himself a novelist), where he grows up in the favored status afforded one of the ruling elite, and then at last returns to the United States as a youth to fulfill his destiny as an adult by becoming a writer. Could you buy that? It sounds like something Sidney Sheldon might think up.

That, however, is substantially the story that Joel Agee has to tell, at least the part of the story that takes place in East Germany. The book begins with him on the way there at the age of 8 and ends with him on the way back at 20. In between, a surprising amount of what he has to say seems simply to be the ordinary story of a boy growing up -- the kind of story, in fact, that was treated by his father in his short novel "The Morning Watch." Joel Agee describes how he would take this book of his father's with him into the woods and how it would make him see and hear better things all around him: "What other writer could charge words with this kind of magic? None! I felt hugely proud. Was it farfetched to imagine that he had written this for me, or at least with me in mind?"

Joel Agee goes on to tell how sketchy his direct knowledge of his father really was: He was only a year old when his parents split up; his mother, Alma, married the German Communist, Bodo Uhse, a veteran of the Spanish Civil War, and told Joel that Uhse was his father. James Agee had agreed with his former wife that this would be best for Joel. "But I remembered him," Joel Agee recalls of James Agee. "He was that big kind friend of Alma's who used to pick me up at the house where we lived on Gay Street in Greenwich Village . . . from there we would walk to Washington Square Park to feed the squirrels peanuts." But by the time, as an adolescent in East Germany, he began carrying that book around as a kind of talisman, Joel Agee was well aware who his real father was.

There is a recurrent motif in the work of the mystery writer Ross Macdonald, the so-called "prince in the poorhouse theme": A young man grows up, usually in humble circumstances, convinced he is something more than what he has been told, that he has a secret identity of sorts -- only to discover upon reaching adulthood that indeed he is somebody special, or at least the son of somebody, and that he must claim his patrimony. This must have been how Joel Agee felt all those years in Gross-Glienicke, East Germany, going to school, writing odes in German, indoctrinated every day with anti-American propaganda, some of which he believed and some of which he didn't. He knew he wasn't who they thought he was. Even when his father died, just about the time plans were being made to bring Joel over to America for a visit, this changed nothing. He was still James Agee's son.

This secret knowledge did not have an altogether happy effect on Joel. He became indolent, unwilling to work in school or elsewhere, evidently so convinced of his own superiority that he felt no need to demonstrate it. He failed two grades, lost the chance to attend a university, and wound up his stay in East Germany working in a shipyard: "There were laws obliging me to either work or go to school."

If his mother got him into this situation, it was she, too, who got him out. For as he was making a mess of his adolescence, she was suffering through the death throes of another marriage. When at least she separated from Bodo Uhse, she made preparations to return to America with her two sons -- Joel and Stefan, the child she had had with Uhse. She informed Joel of her decision: "I acknowledged this bit of news with a stoic nod, but actually I was extremely happy about it. To leave everything, just like that! To start a new life unencumbered by my long string of failures -- in America, where no one would know me! This was nothing less than a complete reprieve." And so they departed.

This is a difficult book to judge, for between its covers are contained two or three books. As an autobiography it is somewhat marred, since its protagonist is not a completely attractive sort. As a memoir of those with whom he grew up it is a good deal more successful: He renders his stepfather with considerable sensitivity, a tragic figure who died two years after the family's departure. It is best of all, however, a document of life in the German Democratic Republic, terra incognita for most of us. As a guide Joel Agee is quite successful; without making it unattractive, he manages to make it seem most familiar.