Could a battalion of U.S. marines, transported back in time, destroy the entire Roman Empire?

That question changed James Erwin's life. It was posted on the website Reddit in 2011, just one of many hypothetical queries posted on the popular forum  where readers engage in lively debate and discussion.

Erwin, a technical writer and historian, saw the question and decided to spend his hour-long lunch break drafting a story about just such a scenario.

By the time lunch was over, he had posted eight pages written in the form of a diary by a U.S. marine whose battalion is mysteriously transported from Afghanistan to ancient Rome.

When he got home from work, Erwin's story titled "Rome Sweet Rome," had been read by 250,000 people and he had been contacted by a talent management firm in L.A. who wanted to work with him.

Readers had even created hypothetical soundtracks for the movie, posters and a fake trailer. And before the week was done, producer of the film "300," Gianni Nunnari, said he wanted to be involved.

"When I first started writing I thought well, this will be a fun way to kill a lunch hour, I thought maybe a hundred fellow nerds would see it and it ended up changing the trajectory of my entire life," Erwin told CTV's Canada AM in an interview from his home in Iowa Tuesday.

"A month after I'd posted this eight-page story I had a manager in Hollywood and I had a deal with Warner Brothers to write a screenplay based upon that story."

Warner Bros made Erwin an offer he couldn't refuse (and isn't disclosing for legal reasons), and he took a leave of absence from his job to write a treatment of the film, and then a screenplay.

Erwin had been writing software manuals at the time, and before that a 700,000-word encyclopedia covering U.S. military history. He had also recently read about a Roman senator who plotted against Augustus. He said he was able to combine the two worlds into one compelling story.

"I think just having that sort of apprenticeship and the ability to sit down, block things out and just start typing, I couldn't have put out eight pages in an hour and I certainly couldn't have possibly written a screenplay three months later without that," said Erwin, who is also a two-time Jeopardy champion.

That screenplay is now being worked on by a second writer, something Erwin said is common in Hollywood, and the project is still slated to go forward. Meanwhile, he has returned to his old job and is anxious to see what's next for the project.

"We're two years in and the second draft is pretty close to being done," he said. "At that point they'll look at it, maybe tweak it again and then maybe they'll say it's ready and go out and find a producer director and stars."