The future of OpenAI was thrown into chaos Monday after nearly all the employees at the artificial intelligence company threatened to quit and join ousted CEO Sam Altman at Microsoft, extending the dramatic Silicon Valley boardroom saga.

More than 700 of the company’s roughly 770 employees have signed a letter threatening to quit unless the current board resigns and reappoints Altman as CEO, according to a person familiar with the matter. In a bizarre twist, it included among the signatories Ilya Sutskever, the company’s chief scientist and a key member of the company’s four-person board, who voted to oust Altman on Friday.

“Your actions have made it obvious that you are incapable of overseeing OpenAI,” the employees wrote in the letter. “We are unable to work for or with people that lack competence, judgment and care for our mission and employees.”

The potential mass exodus at OpenAI puts the entire future of the artificial intelligence lab in doubt, a drastic change of fate for a company that, until just days ago, was considered one of the most promising startups in Silicon Valley with a valuation close to $90 billion. Its swift demise would leave a black hole in the center of the AI industry, allowing Big Tech giants like Microsoft and Google to amass even more control over the powerful new AI technology that is increasingly finding its way into people’s lives. Thousands of startups who rely on OpenAI’s technology would need to find a new provider or face shutting down their businesses.

The hundreds of employees who signed the letter include other senior executives such as chief technology officer Mira Murati, who had been named interim CEO by the board on Friday but replaced by Emmett Shear on Sunday; chief operating officer Brad Lightcap; chief strategy officer Jason Kwon; and head of safety Lillian Weng. Many of the company’s top researchers, AI luminaries who can command salaries in the tens of millions of dollars, also signed, including Wojciech Zaremba, Alec Radford and Bob McCrew. Without them, OpenAI would struggle to keep up with other research labs run by Google, Facebook and Anthropic AI.

Jan Leike, a senior OpenAI executive and well-respected researcher in the broader AI community who was seen Sunday going in and out of the company’s offices, said Monday on X that “the OpenAI board should resign.”

The latest development comes after a chaotic, rapidly changing weekend for OpenAI. On Friday, its board abruptly removed Altman from his role as chief executive, saying he was “not consistently candid” in his communications. That set off a dizzying two-day period during which Altman returned to company headquarters to negotiate his potential return to the artificial intelligence lab, only to see those negotiations collapse Sunday night into early Monday morning, when Microsoft announced Altman was joining the company, along with Greg Brockman, the former OpenAI president who had also quit Friday with Altman in solidarity. Late Sunday, OpenAI’s board said it would back its ouster of Altman and appointed Shear, the co-founder of Twitch, a popular video game streaming platform, as interim CEO.

After several days of being jeered by Silicon Valley heavyweights for ousting Altman, Sutskever on Monday appeared to switch his allegiance. “I deeply regret my participation in the board’s actions. I never intended to harm OpenAI,” Sutskever wrote in a post on X, formerly Twitter. “I love everything we’ve built together and I will do everything I can to reunite the company.”

Altman and Brockman embraced the message, retweeting Sutskever’s post with heart emojis. Bewildered observers tried to keep up with the twist and turns of Silicon Valley’s fastest swinging boardroom showdown.

Much of what employees are feeling played out publicly on X, as dozens of employees at OpenAI signaled their support for Altman: “OpenAI is nothing without its people.” Three high-level researchers who left OpenAI on Friday after Altman was ousted are joining Microsoft, according to Brockman’s post on X. They include the AI lab’s former research director Jakub Pachocki, previous head of preparedness Aleksander Madry and former researcher Szymon Sidor.

Altman’s ouster highlights a major rift in the AI world, where some people believe that the tech should be rushed forward with minimal government regulation to make money and provide helpful tools to people, while others are concerned that it could quickly surpass human intelligence and turn on its creators. OpenAI was initially founded as a nonprofit to provide a counter to Big Tech’s power in AI, but as the company took on more investment money and began developing consumer products, some in the industry said it had abandoned its mission.

“Honestly, it is heartbreaking to see such a world-changing organization be ripped apart,” said Sarah Guo, a venture capitalist and founder of Conviction. “The previous standard-bearer for the AI revolution, the unassailable giant in the room is vulnerable, and new leadership will have their work cut out for them to build customer and employee trust. This completely changes the strategic landscape and emboldens every other player.”

Shear said in a statement that he took the interim CEO job after “reflecting on it for just a few hours,” and said he has a “three point plan for the company” during the first 30 days of his term. It includes the hiring of an independent investigator to “dig into” the company turmoil and reforming OpenAI’s management and leadership team in light of recent departures, he said.

“OpenAI’s stability and success are too important to allow turmoil to disrupt them like this,” Shear added.