In October 1937, young Boston law graduate Phil Parker drives New Hampshire back roads agonizing over whether to join his father's prestigious firm or open his own practice in the small town of Curry, where he loves the land and hopes to marry Sally Ann Allburton despite her father Ted's threat to forbid the marriage. He encounters a mysterious roadside vendor calling himself the Answer Man, who charges $25 for five minutes of answers. After wasting free questions, Phil pays and learns Sally will marry him, they will live in Curry and be happy, the Allburtons will reconcile in seven years, war is coming, America will join in four years and two months, and Phil himself will neither be hurt nor killed. Phil blacks out, awakens in his car, and dismisses it as a dream, but resolves to choose Curry.

Phil and Sally Ann marry in 1938 and build a successful practice in Curry, defending farmers against predatory banks. After Pearl Harbor, Phil enlists. On Eniwetok in 1944, trusting the Answer Man's prophecy, he charges Japanese machine-gunners; bullets riddle his clothes but never touch him. He earns the Medal of Honor and returns home to meet his young son Jake. The town prospers; the Allburtons reconcile, exactly as predicted.

In 1951, Phil encounters the Answer Man again at a new location. Prices have risen. Phil learns he won't be tapped for the U.S. Senate and, devastatingly, that Jake will never play organized ball at any level. When he tries to ask if Jake is okay, time runs out and he tries to pay more, only to find the price doubled and free answers gone. He blacks out again. Months later Jake develops acute lymphocytic leukemia and dies in March 1953 at age ten.

Sally Ann descends into alcoholism. After years of decline, she dies in a drunk-driving crash on election night 1960; her father suffers a fatal heart attack on hearing the news. Phil returns to the empty lot demanding answers from the Answer Man, but no one comes. He sinks into depression until 1964, when Christine Lacasse, the disfigured "Burned Woman," hires him to sue New England Freedom Corporation over the faulty Christmas-light wiring that killed her family. Phil pursues the case for years, channeling his grief and rage; Christine dies of pneumonia, but Phil ultimately wins 7.4 million dollars. He hangs a photo of the Lacasses with the motto "ALWAYS REMEMBER OTHERS HAVE IT WORSE."

Phil takes more pro bono cases, never remarries, finds companionship with Sarah Coombes and his beagle Frank, and becomes Curry's most beloved citizen. In 1995, diagnosed with an inoperable brain tumor, he refuses surgery. On a final drive in October 1995, he encounters the Answer Man one last time, all answers now free. Phil asks whether we go on after death; the Answer Man says yes. To his cascade of follow-up questions about heaven, hell, reunion with loved ones, and emotion, the Answer Man simply replies, "Yes." Phil wakes in his car, headache-free, and drives home, talking to his long-dead dog.