In his widely translated and acclaimed novel "The Reader," Bernhard Schlink took up the dark legacy of the Third Reich, as did Günter Grass and Heinrich Böll before him. He does it again in "Homecoming," a novel that explores the shame the postwar generation feels and whether it, too, must take up the burden of guilt. At the same time, the children of war (and perhaps genocide) desperately try to distance themselves from their elders as if fearing contamination.

The book is a thriller, involving false identities and lots of enticing plot turns, but it has a grave and painful heart. The sober, laconic prose tells you it means business, even as it entertains.

The novel begins quietly, in a seeming paradise. The narrator, Peter Debauer, remembers long, happy summer vacations with his paternal grandparents in their Swiss lake house, which give him a respite from his bleak life with an emotionally cold single mother in Germany.

One year, they send him home with the galleys of one of the popular novels they edit. Don't read the trashy stuff, they admonish; just use the blank sides for schoolwork. A serious and dutiful boy, Peter obeys until some years later, in a fit of boredom, he does read it. By now, whole sections of the book, including the end, are missing, but the plot haunts him: Long after the war, Karl, a German soldier, makes his way home through many travails from a Siberian POW camp, to find that his wife has remarried.

What happens next? the boy wonders.

The adult Peter, unpacking boxes after a move, comes across the novel again. We read portions with him, realizing, as he does, that the plot and structure are based on "The Odyssey." But later homecoming fables, such as "The Return of Martin Guerre," propose a counter-story -- not of triumphant return, but of tra- gedy. Does Karl/Odysseus kill the interloper and leave quietly, or is the real Karl dead and the man at the door an impostor?

Peter dreams of the house and, waking, realizes he has seen it. So the author must be a local man, who perhaps has written a disguised autobiography.

During his private-eye search for the author, Peter lives out yet another version of homecoming.

One day, his live-in girlfriend's sometime lover (or is he her husband?) shows up at their door. Peter flees and cuts all ties to his lover, unwilling to find out whom she would choose.

He is an orderly, somewhat cold and defensive man, given to unpredictable fits of malice and rage. His language is formal, wary, over-controlled, keeping a precarious lid on seething emotions. The excellent and always tone-sensitive translator, Michael Henry Heim, renders it beautifully.

Peter's rigidity makes a sharp contrast to the man he is pursuing. From the accumulating clues, the figure of a charming, seductive, pliable schemer emerges: the changeling as con man. He had altered his name and life many times, and changed his political spots as the need arose, now a Nazi propagandist, now a Communist shill. In each guise, he tortures logic to justify whichever regime he's defending. He claims that no act is intrinsically good or evil. He opposes the golden rule with an iron one: "Whatever you are willing to take on yourself, you have the right to inflict upon others."

One day, Peter, a textbook editor, receives a manuscript called "The Odyssey of Law," by a world-famous professor at Columbia University. The book's language reads ominously like propaganda essays. Assuming a false identity (and not for the first time), Peter goes to New York City and manages to ingratiate himself with the great man whose identity he has figured out.

In its climax, the novel takes a strange and hectic turn involving law students stranded at a country house who unwittingly become guinea pigs in a truly weird social experiment. Schlink, like his protagonist, can't find closure, much less resolution.

With the dispassionate thoroughness of the lawyer he is, he forces us to consider the dilemma of the children of World War II: Are they morally obligated to renounce their elders? The basic conundrum author and characters can't resolve is this: If you understand how something happens, you judge it less harshly. But if you judge harshly, you will not be able to understand.

Brigitte Frase of Minneapolis also reviews books for the Los Angeles Times.