Like a fast-moving storm front, dark clouds of emotion dart across Tom Glenn's eyes as he speaks calmly of the horrors of war.
Gruesome images from Vietnam — where Glenn took part in multiple covert intelligence missions for the National Security Agency between 1962 and 1975 — often well up in his mind's eye from a reservoir of torment deep within him.
While the Ellicott City resident can't halt the excruciating memories from spilling over into his day-to-day life, he has learned to curb their intrusion by pouring himself into writing fiction.
To that end, the spy-turned-author's fourth book is coming out March 15.
"Last of the Annamese" is a historically accurate and semi-autobiographical novel about the last days of the Vietnam War and the fall of Saigon in 1975, from which Glenn escaped under fire.
Glenn weaves a harrowing tale based on his real-life undercover exploits, but his successful career in espionage came at a high price.
At age 80, the 30-year civilian employee of the NSA — who also worked as a linguist and cryptologist for the top-secret agency at Fort Meade before retiring in 1992 — still suffers from post-traumatic stress disorder.
"When a soldier is shot so many times that his head nearly comes off and he drops dead right in front of you ..." Glenn said, pausing to edit his thoughts. "And that was one of the less gruesome things I witnessed."
Nearly a third of Vietnam veterans have had PTSD in their lifetime, estimates the U.S. Department of Veteran Affairs.
Glenn returned to the United States numerous times between undercover missions in Vietnam, arriving in San Francisco alongside U.S. troops returning from war. They were often met by mobs of Americans who screamed "butchers" and "baby killers" and even spat on them, he recalled.
"They blamed the troops for our government's decisions," he said. "That repeatedly tore me up."
Though his first book, "Friendly Casualties," was self-published in 2012, Glenn points out that he spent 15 years working simultaneously on all four of his novels before his recent successes.
"Vietnam didn't sell at all for a while. No one wanted to talk about it or hear about it for 20 years," he said. "But the younger generation doesn't have feelings of disgust or shame, just curiosity, so Vietnam stories are selling now."
Robin Noonan, sales manager at Naval Institute Press — the Annapolis-based publisher of Glenn's latest book — wrote in an email that the author writes from a unique point-of-view because he served in the Vietnam War as a civilian.
"His connection with NSA was classified; his name was redacted from public NSA documents," Noonan said about Glenn's work in signals intelligence, where he intercepted and exploited communications from the invading North Vietnamese.
While Glenn was still at work on his novel, his efforts got a huge boost in 2015 when his combat history was declassified, enabling him to tell more of the real story, Noonan said.
Glenn based the title of "Last of the Annamese" on a plot line involving the use of an old name for South Vietnam, which was An Nam, he said. After the North Vietnamese won the war, South Vietnam and North Vietnam were reunified as one country.
The novelist draws inspiration for his writing style from Ernest Hemingway, whose outlook he doesn't agree with, but whom he refers to as "a master craftsman."
He is also fascinated by the way his own writing unfolds, almost like an out-of-body experience.
"It feels like there's a muse [over my shoulder] and I'm watching a scene and writing about it as fast as I can," he said. "My characters come to me fully formed while I'm in a semi-meditative state."
The author writes for hours on end, only pulling himself away to attend to household chores since he is estranged from his third wife and lives alone. He doesn't own a TV, and prefers to spend his downtime reading.
Eric Goodman, a fellow Baltimore-area author, read the manuscript for Glenn's latest novel before it was submitted and admires his friend's talent.
"Tom's writing is both brutal and sensitive at the same time," he said. "And you can learn a lot about the nuances of history from his books."
But beyond his writing, Glenn has such a diverse array of skills that the Rodgers Forge resident likes to describe him as "the real 'Most Interesting Man in the World.'"
Goodman is referring to the tag line from a series of Dos Equis beer commercials that featured the exploits of a rugged man of incredible talents as portrayed by actor Jonathan Goldsmith, whom Glenn physically resembles.
Glenn fills the "most interesting" bill nicely since he speaks seven languages; plays classical music on a nine-foot Steinway grand piano that dominates his living room; and has advanced degrees in music, government, Chinese and public administration.
Gaithersburg novelist Larry Matthews said that Glenn has led a life "that Indiana Jones would envy," but emphasized that his backstory is also compelling.
The broadcast journalist-turned author wrote about Glenn and six other men in his 2016 nonfiction book, "Age in Good Time." It is subtitled, "Lives and Lessons from Seven Men in their Seventies."
"All of the men [I wrote about] grew up in an America that no longer exists and in many ways, that's a good thing," Matthews said.
His book details the familial hardships Glenn endured as a child and his diagnosis as a slow learner, biographical information that flies in the face of his many accomplishments. The author also marvels at Glenn's resolve to succeed at a second career late in life despite PTSD.
"Tom is paying a very high price for his time in Vietnam," Matthews said. "We [as a country] ask people to go off and do things in our name without considering the human cost."
Glenn has submitted another book manuscript that he has titled, "Secretocracy." It delves into "the most secret time in U.S. government, a period that began in the Ronald Reagan administration, but is mostly set in the novel during the George W. Bush years," he said.
He is also developing other ideas for novels on a variety of topics.
Glenn said he takes pains to impress upon younger writers that "fiction-writing is a craft that requires your whole life and, even then, you'll never perfect it."
He regards his own work as an author as a delicate balancing act.
"Writing down what happened in Vietnam forces me to face it," he said. "I can't keep hiding from it — the dreams, the flashbacks, the rage. Writing doesn't really solve anything, but it definitely helps."