It's eight weeks since 9/11 and security is tight at the Time Warner building in midtown Manhattan. PW has to pass four checkpoints, two demanding photo ID, to reach the elevators. We're here to see David Baldacci, who's in town to generate enthusiasm for his new novel, Last Man Standing .

The book marks Baldacci's return to thrillers after the rural family drama Wish You Well . Its heroes are the FBI's Hostage Rescue Team (HRT), selected from the same Special Forces now fighting in Afghanistan. The book's jacket features Baldacci's name bannered above the title; its sole image is an American flag boldly flapping. The message is patriotism, of honor and resolve in the face of adversity. A cynic might wonder if the flag was included only after September 11.

The flag resembles bunting used on whistlestop railroad tours of the 19th century. Yesterday Baldacci gave a contemporary spin to those tours, boarding an Amtrak Acela at D.C.'s Union Station to sign copies of Last Man Standing as the train chugged north. Proceeds will go to the American Red Cross Disaster Relief Fund, to help victims of the terrorist attacks. Tomorrow he'll sign on a train heading back to Washington. This afternoon he looks a bit worn as we greet him at a conference table inside the Warner Books offices. What about the flag on the jacket, we ask?

It was chosen in June, Baldacci says. He had rejected an initial cover showing a man running. "I said, 'all I want is a flag. The flag is the right thing for this cover.' " There's a plate of fruit and pastries on the table, and fresh coffee. The people at Warner treat Baldacci well. Each of his novels has been an international bestseller, starting with Absolute Power in 1996. That Baldacci can ask for a flag and get it speaks of the house's regard for him and his market savvy.

As befits the corporate litigator he was for a dozen years, Baldacci, who's 41, is wearing a suit and tie. He no longer practices law but acknowledges its influence on his writing: "As a lawyer, I would concentrate on the details and I would think about how those details can be turned into great consequences." Though he'd written stories since childhood, Baldacci considered writing as only a serious sideline, until he turned hobby into profession by applying his attorney's skills to the creation of Absolute Power . Why, though, did he write a thriller to begin with?

"The genre of the thriller is a way for very clever people to show what they can do." Baldacci was born and lives in Virginia but there's no drawl in his rapid responses. "It's a game between me and the reader." He'd read lots of thrillers, he explains, and thought, "I can do just as good. I have this idea about a president and a tryst and a coverup, let's see what I can do." When he finished Absolute Power , he linked up with literary agent Jason Priest, who sold the novel to Warner. He has been with both Priest and Warner ever since.

Immediately compared upon publication of Absolute Power to another southern attorney—turned-novelist, Baldacci never quite shook the Grisham shadow through four subsequent thrillers that revealed him as a storyteller of great skill, if not depth, and one with sustained appeal; he has over 25 million copies in print, in more than 30 languages. Then last year he published Wish You Well, based partly on the hardscrabble life of his mother's family in the Virginia mountains. Near to his heart, the book inspired him to new levels of writing, demonstrating his range and also his ability to produce a novel of real emotional truth. "The techniques and the style, the descriptiveness and the character development readers saw in Wish You Well have carried over into Last Man Standing ," Baldacci insists; and he's right: rife with conflict and sorrow, this densely plotted thriller is his best to date.

Baldacci doesn't write at set times. He composes "in bursts" and only after "I think about it--the smallest minutiae. When I've got all the pieces together in my head, then I sit down and write. I can write on a plane, on a train, in a car with a screaming kid on my lap." Working like that demands a focus that Baldacci demonstrates by never rising from his chair during our long talk, and by reaching out only once to pick at some food. That intensity allows him to conserve time for activities other than writing, including developing, along with Ken Follett and Robert B. Parker, a TV series for Paramount. He serves as ambassador for the National Multiple Sclerosis Society (his sister suffers from the disease) and devotes a lot of time to other charities, particularly literacy causes, while maintaining a stable domestic life with his wife, two sons and an extended family that, he notes, looks to him as "the family patriarch."

"I think I've laid out my life pretty much the way I wanted," Baldacci says, and in many ways, this amiable, handsome, articulate author seems the fulfillment of an American dream, of responsible living rewarded by worldly success. His mother, who's part Cherokee ("the high cheekbones," Baldacci remarks), and his father, a first-generation Italian-American who worked as a trucking firm foreman, instilled in him "the attitude that, if I work hard and respect others, life turns out okay."

"I've tried to follow that," Baldacci says. As he walks us to the elevator, we spot a carton packed with copies of Last Man Standing . The flush of reds, whites and blues reminds us of all the flags flying in this country, and of the values they represent; values, it seems to us, not only smartly celebrated by Baldacci in his new novel, whose heroes combat a domestic terrorist group to tragic result, but embodied by this author, who, when we ask him exactly why he's riding trains and signing books to help victims of 9/11, answers, "It's the right thing to do."