“There are a thousand reasons you shouldn’t do this with Netflix,” he told Fincher, but one big reason he should: The tantalizing offer of two full, 13-episode seasons, guaranteed upfront. No ratings to worry about. No time slots to battle over. Netflix was committing to purchasing 26 hours of original content with essentially no artistic interference. In return, the company would get a flagship show with a movie-star cast and an Academy Award-nominated executive producer. And it would launch not only as the first big show on Netflix but also as the first big show not on traditional TV. When you look at it that way, it made perfect sense to all involved.

Despite his full name — Pack Beauregard Willimon — and the provenance of his lead character, Willimon is not from the Deep South. His father was in the Navy, and Willimon was born in Virginia and grew up mostly in Philadelphia and later St. Louis after his father retired from the Navy to become a lawyer. Willimon then headed to New York to study at Columbia. After he graduated, he got a temporary job in Estonia, working for the government, sorting through thousands of pages of E.U.-related documents and writing summaries of them. This is when he had his breakdown — “partly because the sun never set, and partly because I didn’t know what I was doing with my life, and partly because there’s a dark side of me that can surface from time to time,” he says. “I had panic attacks, depression, all those sorts of things, and I was 3,000 miles from anyone I knew or cared about. I came back to New York, and that sort of continued, and there wasn’t any light at the end of the tunnel. So I went back to St Louis to stay with my parents for a few months and get back on track.”

He eventually returned to New York and was accepted into Columbia’s M.F.A. playwriting program. “I was the worst student by far in our group. A lot of these people had known they wanted to be playwrights forever. I didn’t know a soul in the theater world, and I didn’t have the faintest idea how to truly write a play. But I quit drinking then and really committed myself to this path.”

As an undergrad, Willimon helped out on a few political campaigns, starting with the Senate bid in 1998 of Charles Schumer, who would upset the incumbent, Alfonse D’Amato. This gave him a taste for politics — and inspiration for his play “Farragut North,” which he sent out to 40 theaters around the country, all of which rejected it. But he was able to land an agent, who shopped it in Hollywood, and Warner Bros. eventually bought it to turn it into the George Clooney film “The Ides of March,” which Willimon adapted, and which, more than anything, led to his being the show runner and fervid brain behind the darkest political show ever made.

There are few things that Willimon likes to talk about more than writing, and so the writers’ room of “House of Cards” feels a bit like a graduate seminar on character development, led by a particularly enthusiastic young professor. For this past season, the writers’ room was located in a rented loft in TriBeCa, with a wide-planked timber floor and exposed brick walls. A huge whiteboard contained an episode-by-episode breakdown, with updates on every character, even minor ones, and it took roughly five seconds of scanning the board for me to encounter what qualifies as a super-duper-double-major spoiler.

Meanwhile, Willimon stood in front of a table full of writers and spoke, while the writers, many of them playwrights whose work he admired, sat and listened and occasionally chimed in. One writer, whose back was toward me, idly surfed the Internet: He researched a plane ticket, then checked out an Airbnb listing for a tropical getaway for $99 a night, then bought some camping gear, then browsed an article with the headline “The Top Five Regrets of the Dying.”

Most of the wide-ranging conversation wasn’t about untangling particularly knotty plot considerations but rather, more grandly, about character. Why would someone do that? was a question Willimon circled back to again and again. For all its treachery and dark machinations, “House of Cards” is, in the end, about characters. The show’s most interesting dynamic is between Francis and his wife, Claire, who started out as a kind of familiar Lady Macbeth-style evil-whisperer but has since flowered into one of the more fascinating female characters on TV. (Robin Wright won this year’s Golden Globe for best actress in a dramatic series, beating out, among others, Kerry Washington and Julianna Margulies, which might have seemed like an upset only to anyone who has never watched “House of Cards.”) The whole show could easily be retitled “Scenes From a Marriage,” assuming the average marriage vows were recast as “for richer or poorer, in sickness and in health, and in ambition and venality and mutual gain, forever and ever, always.”