About 15 minutes into Weiner, Elyse Steinberg and Josh Kriegman’s extraordinary documentary about the implosion of Anthony Weiner’s 2013 campaign for mayor of New York, comes a startling revelation from the candidate about his wife, Huma Abedin, the longtime confidante of Hillary Clinton. Weiner turns to Kriegman, manning the camera, and articulates what lots of people have always thought about Abedin: that she is enigmatic to a point of incomprehension. Hearing her voice for the first time on-camera is, Weiner says, “like hearing Charlie Chaplin in the talkies for the first time.” Then, he noted, rather insightfully, “If she were the candidate, I’d be getting crushed.”

It’s a poignant moment because it is candid, perceptive, and real. For all Abedin’s time in the spotlight as Clinton’s gatekeeper—standing by her side at the Gay Pride parade, or whispering in her ear during the 11-hour Benghazi hearing—she remains largely a cipher, a point she essentially admits in the film during a fund-raiser at a Park Avenue apartment. She rarely speaks in public unless she is executing the stilted locutions required by her professional responsibilities. She also rarely cooperates with profiles about her, unless the topic is her son, Jordan, (in People) or when she is transparently navigating a political playbook to return her husband to prominence (The New York Times Magazine). She did not speak to me for my V.F. profile of her published earlier this year.

As I reported my story, speaking to dozens of people in and around Clinton World, I asked the same inevitable question again and again: How was it that Abedin, who appears so charismatic and disciplined, remains married to Weiner, a hothead who has a propensity to document his nether regions on social media? This being the Clintons, no one wanted to speak on the record, but they did offer a compelling picture.

First of all, many of my sources made clear that, once upon a time, Weiner and Abedin shared a genuine chemistry. Part of this was circumstantial, many noted. They were both on steep, political trajectories in Washington and the possibilities must have seemed endless. He was a protégé of New York senator Chuck Schumer, and she, of course, had devoted herself without interruption to Clinton. Other sources suggested, however, that it was actually their differences that brought them together. Weiner, the flamboyant Jewish kid from New York, courted Abedin, the seemingly shy and retiring Muslim, who was born in Michigan (both her parents were professors), but spent most of her childhood in Saudi Arabia. In other words, they could not have been more different, and one of the first rules of physical chemistry must have kicked in: opposites attracted, and they fell in love. (A spokesperson for Abedin did not return a request for comment.)

This chemistry is on obvious display in the first part of Weiner, before his second sexting scandal erupted. When Weiner is leading in the polls, Abedin is playing the supportive wife, giving a speech—“We love this city,” she says at one point early on, “and no one will work harder to make it better than Anthony”—and making a campaign appearance. Along with her large Louis Vuitton satchel, Abedin seems to have accepted her fate as Mrs. Weiner, along with the responsibilities that are part of trying to get her husband elected mayor. We learn in Weiner for instance, that she’s the one who wanted him to run for mayor in the first place in order to resurrect his career. “She was very eager to get her life back that I had taken from her,” Weiner says at one point, “to clean up the mess I had made, and running for mayor was the straightest line to do that.”