Lucinda Franks begins “My Father’s Secret War” (Miramax, 320 pages, $24.95) with a prologue about learning to ride her bicycle with no hands. She starts at the top of a hill above their house, knowing that her father is waiting in the driveway, straddling his own bicycle and smiling. As she gathers speed, she lets go of the handlebars and soars down the hill, arms raised to the sky — only to lose the brakes and end up careering right into her father. “And,” she writes, “there is this peace, this tender happiness as I lie still upon his chest beneath the spinning wheel.”

No doubt Ms. Franks, a Pulitzer-Prize-winning reporter and a masterful wordsmith, put that little catastrophe in the prologue because it is such an apt metaphor for the tangle in which she and her father landed toward the end of his life, when Ms. Franks sets out to figure out what he did in World War II. She’d gained a glimpse of the deep waters when a friend of her father’s told her what happened one night in a bar, when someone said something about getting “jewed in a kike store.” Tom Franks leapt from his chair, tackled the fellow, and was close to strangling him before he was pulled off.

Franks had been in the Navy during the war and, after it, an executive of General Alloys. Eventually he lost his marriage and ended up living alone in slovenly circumstances. Some years after the incident in the bar, Ms. Franks had gone to Massachusetts to help put her father’s house in order. She discovers several boxes containing some of her father’s war memorabilia, including snapshots of ships and aircraft, some foreign currency, a square of silky material on which a map has been written in ink with a destination, X, in a circle, and, startlingly, a grayish green military cap with white trim and a Nazi insignia.

The story Ms. Franks unfolds from this is a narrative of intense suspense, as she seeks to find out secrets that, it turns out, had been eating at her father since the war and that he had talked about with almost no one. Ms. Franks is a master at milking this quest for all it’s worth. At one point, she’s pressing him on whether the Iron Cross was part of a uniform he wore in disguise. He claims he can’t remember the mission. “Dad, you have a photographic memory,” she replies. “Not anymore,” he insists. “I think he’s lying,” she writes, “but I try a different tack.” She asks him whether he ever brought weapons behind enemy lines. He lights another cigarillo. “Maybe,” he replies.

“This,” Ms. Franks writes, “is like dredging a river for dead bodies.”

Part of the charm of the narrative — and there is a great deal — is that the story is not only the search for the solution to the mystery of what Tom Franks did during the war but also the story of a daughter’s desire to reconnect with her father in the years when he is going to his grave. And woven through it is Ms. Franks’s story of her own marriage, to Robert Morgenthau, the district attorney of New York County, who had his own remarkable father, who also gave himself to the struggle for our country in World War II.

The tale is beautifully crafted, and by the time Ms. Franks discovers the secret that has been haunting her father since the war — a disclosure that comes about two-thirds of the way through the book — it has become but one of the extraordinary elements of the story. “My Father’s Secret War” delivers its power in its denouement, as Ms. Franks discovers the letters her father wrote to her mother during the war, in which lies what she calls the “map of my other life.”

For those who have wrestled with the problem of life after a war, the astounding dramas of which seem so hard to relate and in comparison to which so much seems so irrelevant, even meaningless, Ms. Franks’s story has much to offer. Where it gains its universality is in the tale of a daughter’s — and father’s — love and the effort to salvage it from the wreckage of postwar life. Ms. Franks brings to that quest the skills of a brilliant and dogged reporter, finding and interviewing members of her father’s secret unit, gaining a feel for what he was like at the height of his powers.

Her last moments with him are in a home for long-term care, as they sit silently together tapping out music from a remembered tune. “When summertime comes and the tiger swallowtails tremble on the bush, their wings transparent gold, striped with ebony like the keys of a piano,” she writes, “this is when I think of Dad. I think of him watching as they float from branch to branch, stopping to sip nectar from each lavender flower on my moon shadow shrub.

“Sometimes, if I lose myself in the rhythm of their graceful motions, my father seems to inhabit me; his body, my body, my mind, his. Then, as quickly as he comes, he will be gone. And I will have to be content with the part of him that endures in me.”