Have you ever wanted something so badly you wished you could just take it? Did you actually steal it, and then justify it to yourself? 

Allison Hoover Bartlett's The Man Who Loved Books Too Much (Riverhead) explores the kleptomaniac lurking inside us all through John Gilkey. He's the Saks Fifth Avenue associate who used customers' credit-card information to steal his way to a collection of rare books valued at more than $100,000. She visits Joseph Beth Booksellers here on Tue., Oct. 12.

Bartlett uncovers Gilkey's story by way of Ken Sanders, a "bibliodick" (rare-book dealer and self-appointed detective) who's determined to catch Gilkey.

Sanders assures Bartlett she'll never find the thief. But she quickly locates Gilkey at San Quentin State Prison, where he has coincidentally just been released after serving time for book theft. Gilkey is polite, well spoken and more than willing to discuss his crimes.

"Within 24 hours of finding this story I thought it could be a book," she says in a phone interview. 

Gilkey begins detailing for her his plans for future theft, implicating the author in the plot. Thus, Bartlett became part of her own story.

Meanwhile, though Gilkey was obviously comfortable telling his story, he never quite forgot that the recorder was running. "I had stepped into the story, whether I liked it or not. The bigger issue was the issue of influence," she says. 

 At one point, he began suggesting alternative endings for the story, endings that Bartlett details for her readers. 

"He kind of joked sometimes that if he only committed a murder or something it would make a better story. And he had no intentions of that, of course; it was a joke."

The book became an ethical challenge as well as a journalistic one. "When you follow a subject around ... when you're asking questions of somebody, it affects how they act, it affects what they say. You can't help influencing the story," she says. It's an issue she wishes more writers would discuss.

By the time she completed the book, Bartlett realized that it had evolved into a commentary on our emotional ties to books and the stories they tell.

"I thought this book was initially about a crime and I realized it was more a book about why people are passionate about books," she says. "People like to explore and discuss the affect of books on their lives." 

Though Bartlett firmly believes Gilkey deserved to be caught and punished, his love of books resonates with readers.

"I can't tell you how many people since I started have told me that they stole a book once, including several authors I know," she says. 

Allison Hoover Bartlett discusses and signs The Man Who Loved Books Too Much at 7 p.m. Tue., Oct. 12, at Joseph-Beth Booksellers (510 S. 27^th St., South Side; 412-381-3600).