After graduating from Vassar, Lucinda Franks went to work for the United Press International in London. She was eager to escape from what she calls her “shipwrecked family.” In 1970, she was sent back to New York to cover the story of an accidental explosion in Greenwich Village that killed three members of the Weathermen, a radical anti-war group.

Franks’ story about one of the victims, written with Thomas Powers, won a Pulitzer Prize. Subsequently, she settled in New York where she wrote regularly for the New York Times and for various magazines. In 1977, Franks married Robert Morgenthau, New York’s District Attorney, son of Henry Morgenthau, Roosevelt’s Hyde Park neighbor and later, his Secretary of the Treasury who helped Jews to escape from the Nazis.

The Morgenthaus were “cultural rather than religious Jews.” They observed the Jewish holidays but also celebrated Christmas.

The focus of Franks’ latest book, My Father’s Secret War, is on her father, Tom, and her determined effort to find out about his military service in World War II.

She knew that he married her mother, Lorraine, in 1941 and that he was commissioned as an ensign in the navy a year later but he was secretive about what he did during the war. Born after the war ended, Franks developed unpleasant relationships with both her parents. Her mother was an obese manic-depressive who died in 1976 when Tom was in his sixties. He was an alcoholic who became vice-president of General Alloys, only to lose his job when the company failed, causing him to become financially dependent on Franks and her sister.

Worst of all, Franks discovered that her father had a mistress almost from the beginning of his marriage.

As Tom developed symptoms of dementia, Franks’s attitude toward him slowly began to change. She was intrigued by the hundred cartons of his belongings and by their mysterious hints of clandestine service during the war. Obsessed by the need to find out what her father had done, Franks pressed him for information and sought out anyone who might supplement the meager facts he reluctantly provided.

She pored through all kinds of military archives and gradually put together the story of his exploits in both the South Pacific and in Europe. She persuaded him to record his experience in helping to liberate a Nazi concentration camp at Ohrdruf for the Museum of Jewish Heritage.

For Tom, what he saw made him always condemn any expression of anti-Semitism and to become a fervent Zionist.

When Tom died in 2002, the memorial service included a eulogy by one rabbi and the recitation of the Kaddish by another rabbi. Franks’ search led her to reconciliation with her father’s memory and even to a relationship with his mistress.

She sees him as a casualty of war who “was my first hero, and now he is my last.”

This moving account of Franks’s insistence on discovering the truth about her father is a profound, well-written narrative that rivets the reader’s attention and that reveals secrets about a family and about World War II.

This new book more than merits all kinds of prizes.

Dr. Morton I. Teicher is the Founding Dean of the Wurzweiler School of Social Work, Yeshiva University and Dean Emeritus, School of Social Work, University of North Carolina-Chapel Hill.

LUCINDA FRANKS, author of “My Father’s Secret War,” published by Hyperion, will speak at 7:30 p.m.on Monday, Nov. 5.

Admission: $12 or free with series ticket