(Reuters) - When researching his forthcoming novel about a serial killer plotting to assassinate the U.S. president, New York Times best-selling author Brad Meltzer went straight to the top: 41st President George H.W. Bush, a fan of the author's work.
"Bush was extremely helpful," Meltzer, 42, told Reuters ahead of the release of "The Fifth Assassin" by Grand Central Publishing on Tuesday.
Meltzer explained that the former president was a fan after reading previous political thrillers he had written.
"Bush wrote me the best fan letter I ever got in my life. Then he invited me to Houston to spend some time with him as I was researching one of the books. We became friends over the course of many years," Meltzer said in a telephone interview.
"I'll always ask him about little details about White House life that only he and a few others could possibly know," the author added.
"But asking a president about the hidden staircase in the White House residence is different than asking him about what it's like to know that someone's out there planning your death."
Asked how he broached such a sensitive subject with Bush, Meltzer, who holds a Columbia law degree, was frank: "Maybe I should be smarter, but I just ask. They've dealt with far worse than me."
"The Fifth Assassin," Meltzer's 12 novel, features the return of hero Beecher White and President Andrew Wallace, characters from Meltzer's previous novel, "The Inner Circle."
White works as an archivist at the U.S. National Archives and belongs to the Culper Ring, a covert network of spies founded by George Washington during the American Revolution.
After White joins the Culper Ring, he learns Wallace is hiding a few sins behind his presidency.
"(White is) part me, part dream," Meltzer said. "Twice as smart as me, but twice as broken. The truth is, I just love that our hero isn't some silly, macho cliche. He's an archivist. His best weapon is his brain."
In the book, White and the Culper Ring are on the trail of a remorseless killer who sets his sights on Wallace.
LINCOLN'S SKULL, ASSASSIN'S BONES
The killer - who may well be someone White knows from his youth - is recreating the crimes of John Wilkes Booth, Charles J. Guiteau, Leon Czolgosz and Lee Harvey Oswald - the assassins of Presidents Abraham Lincoln, James A. Garfield, William McKinley and John F. Kennedy, respectively.
Even more disturbing, White discovers these four presidential assassins may not have been acting alone, contrary to what is written in history books.
Meltzer explained that the idea for the book came during a visit to the little-known U.S. Army-run National Museum of Health and Medicine near Washington.
"It began with a government employee who told me that I needed to come to a museum that almost no one knew about," he said. "Naturally, I was suspicious ... Then he told me, 'We have pieces of Abraham Lincoln's skull, the bullet that killed him and even the bones of John Wilkes Booth, if you want to see them.'
"But as I started looking at the items, I could feel my brain working out the plot of the thriller. What if, over the course of 100 years, the four assassins - from John Wilkes Booth to Lee Harvey Oswald - were secretly working together?"
It is familiar territory for Meltzer, who also hosts "Brad Meltzer's Decoded," a television series on the History Channel where he and a team of experts examine history's mysteries.
Meltzer has also written comic books, including "Buffy the Vampire Slayer" for Dark Horse Comics as well as "Green Arrow" and "Identity Crisis," which featured Superman and Batman, for DC Comics.
His projects after "The Fifth Assassin" include a "Decoded" book, then a children's book and another Beecher White novel.
Grand Central Publishing is an imprint of Hachette Book Group, which is owned by French publisher Hachette Livre, a subsidiary of Lagardere Group.
(Reporting by Kurt Anthony Krug, Editing by Eric Kelsey and David Brunnstrom)