Waiters at a packed Upper East Side espresso bar skittered past the table where Brad Meltzer was discussing his new thriller, "The Fifth Assassin."
But Mr. Meltzer, 42, the energetic and prematurely bald author of best-selling novels like "The Book of Lies," "The Book of Fate" and "The Inner Circle" is such a good talker with such a lot to go on about—his hosting chores on "Decoded," a History Channel show that investigates conspiracy theories; the comic books he's written for the "Green Arrow" and "Buffy the Vampire Slayer" series; the contract he just signed for a line of children's picture books—you barely notice that almost an hour has gone by without anyone taking the cappuccino order.
"That's OK," Mr. Meltzer said, sounding a bit sheepish. "I don't drink coffee."
And why should he? He doesn't seem to need the caffeine. He's fueled by something far stronger: fear of ending up like his father, a topic we're going to get to in just a minute.
There's a plot to kill the president in "The Fifth Assassin," the second installment of a projected trilogy (and like all of Mr. Meltzer's novels, a blend of conspiracy, cliffhanger and historical factoid—the more arcane the better). The warm-up to the nefarious deed involves the ritualistic murder of several clerics using methods that recall the killings of Presidents Lincoln, Garfield, McKinley and Kennedy. Whether the malefactors prevail depends on an amateur gang of gumshoes.
The idea for the book grew out of what Mr. Meltzer said was his involvement in Red Cell, reportedly a program created by the Department of Homeland Security to harness the creativity of out-of-the-box thinkers.
"A couple of years ago, they called and asked me to come and brainstorm different ways terrorists might attack the United States," he recalled. "My first thought was 'if they're calling me, we have bigger problems than anybody thinks.' They paired me with a chemist and a Secret Service agent and gave us a target: destroying a major city in an hour. You do not go home feeling good." (Emails to DHS about the program and Mr. Meltzer's participation were unanswered.)
"I was struck with 'why did they pick me, an ordinary citizen?'" he continued. "I traced it back through history to George Washington, who had his own secret spy ring of ordinary people because no one would look twice at them. And I said to a Secret Service agent I'd met at Homeland Security, 'Wouldn't it be incredible if that spy ring still exists?' And the agent answered, 'Who says it doesn't?'"
The idea of such a citizen's group plays right into the theme that animates the Meltzer oeuvre: the ability of the average guy to effect change. "It's what I think people read my books for," he said.
Mr. Meltzer is fortunate in those readers, both in terms of numbers—"The Book of Fate" has sold 800,000 copies; "The Book of Lies" and "The Inner Circle," 450,000 copies each—and in terms of names. "After George H.W. Bush left office, I got a letter saying that he liked my books and would like an autographed copy," said Mr. Meltzer, who became fast friends with the former leader of the free world, so much so that he was invited to Houston for a visit. But Mr. Bush offered more than hospitality: He provided insider input on "The Book of Fate," a political thriller whose characters include an ex-POTUS, as well as on two subsequent novels—and even contributed a blurb.
"He's helped with small details—like what a president actually keeps on his desk to details that almost no one knows," Mr. Meltzer said. "Like the fact that when you leave the White House, one of the first things they make you do is plan your own funeral."
The elder of two children, Mr. Meltzer grew up in Brooklyn in a decidedly nonliterary household. He learned about the power of storytelling from his grandfather and learned to read from his grandmother, who also took him to the library and introduced him to Agatha Christie mysteries. "There were no books in my home," Mr. Meltzer said. "My mom read the National Enquirer and the Star. She said that was where the real news of the world came from."
His father's business acumen rivaled his mother's journalistic instincts. "My dad lost his job at 39 and decided to move us to Florida," Mr. Meltzer said. "He had no prospects, he wasn't a planner, he wasn't good with money. He couldn't pay babysitters, so we went with him to job interviews. He'd have an interview on one side of a Wendy's and my sister and I were on the other side. I was picking at french fries and thinking, 'My future is being decided at a Wendy's.'" Eventually, the senior Mr. Meltzer got a job selling insurance.
His son, looking for some insurance of his own, followed up college with law school. "I didn't want to be a lawyer. I went out of fear. I was terrified to have my dad's life," said Mr. Meltzer, who sold his first thriller, "The Tenth Justice," while getting his J.D. at Columbia, and has been multitasking and revisiting his childhood ever since. "I watched bad things happen to my father and watched my life disappear," he said. "Not to get all Freudian, but boy, did that have an impact on me. In every one of my books you'll see that moment."
Mr. Meltzer's activities—the books, the comics, the TV show—have accomplished several things: They've furnished a comfortable income (take that, Dr. Freud), provided outlets for the author's creativity and for his prodigious research in the bowels of the National Archives, and have made him increasingly anxiety-ridden. "Anyone who writes thrillers is paranoid," Mr. Meltzer said. And they have guaranteed an endless stream of correspondence.
"No one gets crazier email than me," Mr. Meltzer said. "No one gets more proof that Abraham Lincoln was gay. I get mail about alien encounters, about the moment people met God. Someone brought me the holy grail at a book signing. If you need its regenerative powers, it's at a Barnes & Noble in Los Angeles in the fiction section between Melville and Meltzer." With the publication of "The Fifth Assassin," he's undoubtedly girding himself for a fresh bounty of relics and recondite musings.
Fans, like Mr. Bush, probably wish that Mr. Meltzer would stop moonlighting on "Decoded" and forget this new children's-book diversion so he can devote more time to his day job. Currently, he comes out with a new thriller every two to 2½ years; there are no plans to pick up the pace.
"I have a friend who is one of the top 10 best-selling authors in the country," Mr. Meltzer said. "And he told me, 'If I have to write my character again I'm going to put a gun in my mouth.' He's learned to hate what he loved so much. I never want to be like him. I don't want to be churning them out."
Ms. Kaufman writes about culture for the Journal.
A version of this article appeared January 15, 2013, on page D5 in the U.S. edition of The Wall Street Journal, with the headline: His Plotting Pays Off.