“The Mockingbird Next Door: Life with Harper Lee” by Marja Mills (The Penguin Press, 278 pgs., $27.95)

“Why does the writing make us chase the writer?” Julian Barnes asked in “Flaubert’s Parrot.” “Why can’t we leave well enough alone? Why aren’t the books enough?”

In the case of Harper Lee, there aren’t books, plural, but a book, singular. “To Kill a Mockingbird” was published in 1960, won a Pulitzer Prize and became a classic of American literature. It still sells some 750,000 copies annually. Its author stopped talking to the press in 1965. To those who chase her, who can’t leave well enough alone, she has developed a standard response to their proposed interviews: “Not just no, but hell no.”

There have been peeks inside Lee’s world. Journalists have made the pilgrimage to Monroeville, Alabama, where she has hidden in plain sight all these decades, and have sniffed around. In 2006, Charles Shields published “Mockingbird: A Portrait of Harper Lee,” a not-bad unauthorized biography.

No reporter has gotten closer to this reclusive writer than Marja Mills. In 2001, she flew to Monroeville to write about Lee for The Chicago Tribune. Unexpectedly, she became friendly with Lee, who was 75 at the time, and with her older sister, Alice, then 89. Perhaps these women were lonely; perhaps they saw in Mills the daughter neither had. When Mills went on disability because of health problems, the Lee sisters encouraged her to rent the house next door to theirs.

(Joe McGinniss moved next door to Sarah Palin. Mills gets a place next to Harper Lee. I smell a next-level journalism trend. Beware your perky new neighbors, Thomas Pynchon.)

Mills has now delivered a book, “The Mockingbird Next Door,” about her experience of being Lee’s neighbor. Lee, who is 88 and who moved into a nursing home after having a serious stroke in 2007, is said to be outraged by its appearance in bookstores. (See inset for more details on the dispute.) But it seems plain that she and her sister did invite Mills into their lives and were aware that a book would someday result.

I simply wish it were a good book. “The Mockingbird Next Door” is painfully earnest (the author’s avowed intent is “to honor all that they shared with me”) and as sentimental as “Tuesdays With Morrie.” It doesn’t so much spill the beans about Lee as infantilize her.

Mills repeatedly tells us what good company Lee is. “She was a woman of formidable intellect,” we read, and “the best conversationalist this side of the Mississippi.” If this is true, then Mills is a dire Boswell.

Nearly every direct quotation from Lee is a banality: “Oh, bless his heart.” “Thank you, hon. You are a good egg.” “I don’t know when I’ve enjoyed a meal more.” “Oomph. I’m bushed.” “I shouldn’t have the cheese grits. But I’m going to.” Here she is on quitting smoking: “It’s terribly hard. But it can be done. I went cold turkey.” On fishing: “I never get tired of this.”

Mills gets her on the record as saying about “To Kill a Mockingbird,” in a moment of pique, “I wish I’d never written the damn thing.” Lee’s first name is Nelle, and friends call her that. She criticizes Mills after she writes, in The Tribune, that Alice pronounces her sister’s name “Nail Hah-puh.” Lee told her, “You dropped her two social classes with one syllable.” That’s the Harper Lee one longs to see more of here.

“The Mockingbird Next Door” conjured mostly sad images in my mind. Lee has a regular booth at McDonald’s, where she goes for coffee. She eats takeout salads from Burger King on movie night. When she fishes, she uses wieners for bait. She feeds the town ducks daily, with seed corn from a plastic Cool Whip Free container, calling “Woo-hoo-HOO! Woo-hoo-HOO!” Somehow learning all this is worse than it would be to learn that she steals money from a local orphanage.

There are hints of a life of the mind. She keeps British periodicals in the house: The Spectator, the Times Literary Supplement, The Weekly Telegraph. She talks a bit about her favorite books. Mills doesn’t pick up on much of this. When Lee mentions the British historian Thomas Macaulay’s books, this is what pops into Mills’ head: “Nowadays, ‘Home Alone’ actor Macaulay Culkin has far greater name recognition.”

This book does touch, glancingly, on deeper matters. Lee is said to have a temper, to call people late at night after drinking too much and let fly at them, but Mills never directly experiences this. Speculation that Lee may be gay is allowed to float gently to the surface.

There are scenes in this book that could, in a better writer’s hands, almost be turned into stage plays. Mills watched the 2004 Super Bowl, the one with Janet Jackson’s bared nipple, with Lee. Imagine what Janet Malcolm could do with that scene.

She attends exercise class with her. She watches an advance bootleg copy of the film “Capote,” in which Lee is played by Catherine Keener, with her. But these moments, here, aren’t memorable.

Reading this book put me in mind of a rare public appearance Lee made in Alabama in 2007. “It’s better to be silent,” she told an audience, “than to be a fool.”