Susan Choi's "A Person of Interest" has all the fine ingredients of a page-turner, but its true power lies in its subtle psychological depiction of alienation, guilt and redemption in these edgy times of mistrust and public paranoia.

Professor Lee, an Asian-born mathematician nearing retirement at a Midwestern university, is working in his office when a letter bomb goes off in the office next door. Lee is unhurt, but his popular colleague, Rick Hendley, is killed. Similar bombings have occurred on other campuses and are believed to be the work of a technology-hating madman whom the press has dubbed the Brain Bomber.

Nevertheless, when Lee does not attend a memorial service for Hendley and is evasive with FBI interrogators, he becomes not a suspect but the next thing to it: "a person of interest." Meanwhile, he has received a disturbing letter from a friend from his graduate student days. Was it possible that the bomb was really meant for him, not Hendley?

Now ostracized by town and gown, Lee begins an obsessive examination of the shortcomings that have brought him to this point: the damage he did to a man who befriended him 30 years ago, the love he withheld from his ex-wife, who is now dead, his failures as a father, all the selfishness that has made him a person of interest rather than a person who is loved.

How does a man become so separated from his neighbors, his colleagues, his town? Choi is adept at rendering the joyless sterility of his life -- the cheap, worn-out clothes, the barely furnished house in a depressing subdivision, the equally unfurnished social life. Lee -- aloof, self-justifying and proud -- does not easily engage the reader's sympathy, but his failures resonate with many of our own.

Choi, whose "American Woman" was a Pulitzer Prize finalist in 2004, is a writer with rare gifts. She has an eye for the telling details that reveal complicated, fully developed characters as well as an equally acute sensitivity for the times we live in.

"A Person of Interest" never loses its way, as Choi propels the story in a narrative style that is clear, confident and at times lyrical:

"Outdoors, spring had been sweetly indifferent to the disasters of man, but from this vantage the budding branches Lee saw appeared frozen in postures of horror. It must be the youth of this building, Lee thought; not enough had transpired here for the palimpsest theory to work."

By the end of the novel, Lee has at last learned to know himself, but Choi knows him, and perhaps us, even better.

Marx Swanholm is a freelance writer and retired senior exhibit curator at the Minnesota Historical Society.