"We went up to the campsite and went through a lot of stuff at the location," Stewart said. "It was an emotionally powerful experience. To actually be there at the site and hear the story that happened at that location, you realize what really evil people and what an evil event took place there."
Now Stewart is in the latter stages of writing Smart's memoir a collaborative effort that's taken more than a year to do and hundreds of hours of interviews with the 25-year-old from Salt Lake City made famous after being kidnapped, held prisoner and raped repeatedly by Brian David Mitchell in 2002 and 2003.
The book is set to be released in September 2013 through St. Martin's Press.
By then, Stewart is expected to be deep into doing his other job representing Utah in Congress. The 52-year-old Republican handily beat Democrat Jay Seegmiller in Utah's 2nd Congressional District by almost a 2-to-1 margin Nov. 6 in his first bid for public office.
He said he hopes to have the book's first draft written before he's sworn into office in January.
"The good news is we've made lots of progress," Stewart said from his Farmington home, where he took a short break from raking leaves in his yard. "There will be editing after that, of course."
He said, however, it is important that the focus be entirely on Smart, and he said the memoir will be her story in her voice.
"She went through a dramatic and brutal experience but, despite that, became the optimistic, beautiful person she is," Stewart said. "This is a good person who has a compelling story to tell."
The right writer • The Smart story was a media sensation that took many twists and turns in the more than 10 years since her abduction from her home when she was a 14-year-old sleeping in her parents house in Salt Lake City's Federal Heights neighborhood.
Chris Thomas, spokesman for Smart, said she chose Stewart to help write the book after her father had met him at a book-signing event last year. Thomas said Smart interviewed several potential authors before settling on Stewart.
"The process had taken a lot longer than she anticipated, but it was important for her to get the right writer to collaborate with and the right publisher to tell the story the right way," Thomas said. "She liked his approach not just a story of what happened to her 10 years ago, but what has happened to her in the years since."
Those 10 years have seen Smart testify in court against Mitchell a man who often took to singing in the courtroom while questions about his mental competency to stand trial went back and forth. He finally was convicted in 2011 and received two life sentences for the crimes. Mitchell's accomplice, Wanda Barzee, is serving a 15-year sentence in a Texas prison.
The decade alsosaw Smart go on the speaking circuit to talk about crimes against children and human trafficking as well as working as a correspondent on "Good Morning America." She also set up the Elizabeth Smart Foundation to help stop predatory crimes.
In court, she told Mitchell, "You will never affect me again."
Thomas said the book is a chance for her to "tell her story and give hope to others who have been victims of crimes."
Discretion • Stewart, a former U.S. Air Force pilot, was known mostly as an author who wrote a series of fictional spy novels as well as books about key points in history including "Seven Miracles That Saved America: Why They Matter and Why We Should Have Hope" and "The Miracle of Freedom: Seven Tipping Points That Saved the World."
He said the Smart memoir was unlike anything he'd tackled before.
"It's such an intensely personal event. It was uncomfortable for me at times to ask questions that were going to be uncomfortable to answer," Stewart said. "She's approached this in a very mature fashion and in a truly professional way, which is pretty impressive to me because it was such a dramatic event."
The interviews, he said, mostly took place at his office in Farmington, where he was working as president of The Shipley Group, a consulting firm.
He said it was important to keep the interviews and the writing of the book quiet as he began, in December 2011, the process running for office.
"He has been incredibly discreet," Thomas said. "He didn't in any way want to politicize it and that was important to Elizabeth. He had informed her he was planning to run for office and he made it very clear to her that he didn't want it brought into the campaign either."
Several books about Smart have been written, including "Bringing Elizabeth Home: A Journey of Faith and Hope"by parents Ed Smart and Lois Smart along with writer Laura Morton.
This will be Elizabeth Smart's first memoir.