Earlier this year, I asked Sam Altman whether decisions made by OpenAI’s leaders might one day lead to unemployment among the masses. “Jobs are definitely going to go away, full stop,” he told me. He couldn’t have known then that his would be among the first. In a blog post released this afternoon, OpenAI—the artificial-intelligence juggernaut for which Altman was the CEO—announced that he would be leaving, effective immediately, because, according to the statement, “he was not consistently candid in his communications with the board.”

The statement did not specify the nature of Altman’s alleged misrepresentations, but they must have concerned serious matters to merit such a dramatic and public rebuke. Altman did not reply to multiple texts seeking comment, but in a post on X (formerly Twitter), he said that he’d loved his time at OpenAI, and that it was transformative for him “personally, and hopefully for the world a little bit.”

The suddenness of this announcement, and the Icarus-like fall it represents for Altman, is difficult to overstate. In 2015, Altman convened a now-famous dinner at the Rosewood Sand Hill, in Menlo Park, California, with Elon Musk and a small group of others, at which they agreed to found OpenAI. Various tech luminaries committed $1 billion to the company, including Musk, who agreed to co-chair its board with Altman. Their partnership lasted only until 2018, when Musk made a play to become the company’s CEO, as reported by Semafor. Altman led the resistance and, a year later, assumed the CEO title for himself.

Altman was internet-famous before founding OpenAI, primarily because of his role as the president of Y Combinator, Silicon Valley’s most prestigious start-up accelerator. But after OpenAI released ChatGPT late last year, he became a global celebrity and embarked on a world tour, meeting with more than 10 heads of state. When I joined him for his swing through East Asia last June, he was mobbed with selfie-seekers everywhere we went. He didn’t shy away from his new, larger-than-life image. He told me, and others, that he imagined AI bringing a new kind of society into being. He said that it would be the “greatest golden age.”

[Read: Does Sam Altman know what he’s creating?]

Executives are on their best behavior for reporters, but in speaking with two of Altman’s then–fellow board members, Ilya Sutskever and Greg Brockman, I never heard anything that suggested palace intrigue or even much dissent. Just last week, Satya Nadella, the CEO of Microsoft, the company’s main financial backer, appeared onstage with Altman at the company’s developer day. According to Axios, Microsoft learned about the news only a minute before it was announced, which was one minute earlier than employees at OpenAI reportedly found out. It’s hard to think of an analogue to Altman’s firing; it’d be as if Bill Gates was abruptly shown the door at Microsoft in 1995.

OpenAI has so far stayed ahead of the pack in AI, despite a long and growing list of competitors, including start-ups and tech giants both. In part, it’s done so by remaining largely drama free. That’s over now, and the fallout goes beyond Altman. Brockman, another of the company’s co-founders, announced to OpenAI’s employees that he had resigned, “based on today’s news.” The company’s earlier statement said that he’d retained his position at the company but stepped down as its chairman. Either way, he’s out now too.

Mira Murati, who was formerly the company’s CTO, has been named interim CEO. I’ve sat down with Murati twice, most recently in September, at The Atlantic Festival. Her message was, to my ear, indistinguishable from Altman’s. She told me that OpenAI was pressing forward in trying to build an AI that could transcend human understanding of science. She said that it would be up to society to adapt to this new technology.

But that was before Altman’s ouster. Perhaps Murati will soon articulate some new vision, or perhaps that task will fall to Altman’s permanent replacement. In the meantime, the resonant mystery, the thing that has group texts across Silicon Valley—and, indeed, the world—abuzz with speculation, is what Altman could have done to deserve all this. Was it a colorful indiscretion in his personal life? An internal power play? Did he go rogue in some way? Once we know, we’ll be able to say more about OpenAI’s future, and his.