John Updike can't stop writing -- A half century into his career, the famed author returns with his most surprising novel yet: ''Terrorist''

When the second plane flew into the Twin Towers on 9/11, John Updike and his wife watched the fireball bloom as they stood on a rooftop across the river in Brooklyn, where they were visiting family. ”And then, within an hour,” Updike wrote a week later in The New Yorker, ”the south tower dropped from the screen of our viewing; it fell straight down like an elevator, with a tinkling shiver and a groan of concussion distinct across the mile of air. We knew we had just witnessed thousands of deaths; we clung to each other as if we ourselves were falling.”

These are not images easily erased from your mind; they took up residence in Updike’s head, and now, five years later, he has written a novel called Terrorist (due out June 6 from Knopf), which dares to imagine the interior life of Ahmad, an 18-year-old Islamic radical from inner-city New Jersey who wants to be a martyr. Witnessing the tragedy, says Updike, with typical candor, ”was so awful, and — in its way — exciting. I had no thought of watching it as a writer, but maybe it did give me some acquaintanceship with the world that terrorists hope to achieve.” Leaning on a fresh reading of the Koran and a few other books for research, and on ”my own experience of being an 18-year-old a number of years ago,” he created suicide bomber Ahmad, ”this well-intentioned and in some ways exemplary young man who tries to do something horrific.”

Coming from the 74-year-old Updike — who 48 years ago published the first of his 22 literary fictions, 15 short-story collections, seven books of poetry, eight roundups of essays and criticism, one memoir, one play, and five children’s books — Terrorist is a jolt. His novels are better known for the glories of their delicate observation and beautifully carved sentences than for rip-through-the-pages plotting. Terrorist upends that. ”This book is quite a surprise,” concurs Judith Jones, his Knopf editor for more than 45 years. ”The last 100 pages have you on the edge of your seat. That isn’t the usual Updike, which is more, you know, where you settle in comfortably. But I think it shows a real ability to write that kind of suspense novel.”

Updike seems almost embarrassed to have written a suspense novel. Would he dare go so far as to call Terrorist a thriller? ”Sort of, yes,” he says uneasily. ”Let’s hope it’s an Updike kind of thriller.” By which he means that the novel is, like all his others, first and foremost about everyday life. ”It’s about religion, and growing up, and being a good guidance counselor” — his other main character is Jack Levy, Ahmad’s high school adviser — ”and all those things,” he insists.

You might expect that meeting someone in person who has published so much, who has made such an intimidating play for the title of World’s Greatest Living Writer, would be as daunting as meeting the Ivy League’s scariest professor during office hours. But talking to Updike at the bar in the Ritz-Carlton in Boston, 30 miles from the seaside house he shares with his wife Martha, isn’t like that at all. He is impeccably groomed — except for the unkempt eyebrows that whirl madly around the edges of his tiny eyes. And his bearing is classic New England, gray-suited and stiff-backed — except that from the first moments of a nearly three-hour interview he seems to cap every sentence with a happy, eager-to-please smile, and he’s full of modest yet disarming bombshells. When the talk idly turns to what movies he and the wife have enjoyed recently, the august literary titan mentions Nanny McPhee (”I liked that more than I dared hope, yes”) and 16 Blocks (Bruce Willis, of whom he’s a fan, reminds him of Gary Cooper). And of his own work, Updike is cheerfully self-deprecating. ”I’ve written plenty of novels,” he says at one point. ”Maybe it would’ve been better if I’d written fewer.”