Shortly before 11 a.m. on Sunday, the 80,000 physicians, health scientists, disease detectives, and others tasked with safeguarding the nation’s health received instructions to respond to an email sent the day before asking them, “What did you do last week?”

The email arose from a Saturday dispatch issued by President Donald Trump on the social-media platform he owns, Truth Social. “ELON IS DOING A GREAT JOB, BUT I WOULD LIKE TO SEE HIM GET MORE AGGRESSIVE,” he wrote.

The response from Elon Musk arrived seven hours later on the social-media platform he owns, X. The billionaire Trump confidant leading the effort to slash the federal workforce wrote that afternoon that he was acting on Trump’s “instructions” and ensuring that “all federal employees will shortly receive an email requesting to understand what they got done last week.”

The result was a government-wide email directing federal workers to detail their accomplishments over the previous week, in five bullet points. Musk wrote on X: “Failure to respond will be taken as a resignation.”

The directive sent agencies scrambling to tell their employees what to do. Some instructed them not to respond. Others made clear that a reply was mandatory. And then there was the Department of Health and Human Services—an epicenter of the chaos engulfing Washington.

“This is a legitimate email,” read Sunday morning’s instructions from HHS, which advised employees to respond by the deadline set for 11:59 p.m. ET on Monday.

But later that day, the directions changed. Employees were told to “pause” answering the email, according to new guidance sent Sunday at 5 p.m., which pointed to concerns about the sensitivity of department business. HHS promised that updated guidance would arrive Monday at noon.

By late afternoon on Monday, many federal health workers had left their offices with no new guidance, uncertain about whether to respond to the email and whether ignoring it would jeopardize their jobs.

They didn’t know that the federal government’s main personnel agency, which had sent Saturday’s government-wide email, had quietly instructed agencies midday Monday that a response was voluntary. Those instructions effectively rescinded Musk’s threats.

For Musk, the episode was a setback. For federal workers struggling to get their bearings, they told us it was just one more reason to feel both fury and fear.

“This whole administration is a fucking train wreck,” a federal health official said.

The shifting and contradictory instructions divided Trump’s Cabinet, and for the first time, created daylight between Musk and the White House. Even before the administration formally conceded that responses were voluntary, Trump advisers had privately signaled support for agency heads who told their employees not to reply to the email, owing to the sensitivity of their work.

Most of the pushback to the Musk directive came from the country’s national-security agencies, including the CIA, the FBI, and the Department of Homeland Security. A senior official at NASA, which advised employees not to respond, called the request an “unprecedented ask and unprompted attack on our workforce” in a weekend email to employees that was described to us. A deputy commander at the Navy told people in his chain of command, “Please do NOT respond at this time,” accenting his order using bold red text.

The cascading series of contradictory guidance reflected the unusual balance of power between Trump and Musk, and the unpredictable consequences for millions of federal workers. “It’s a psyop,” said a senior official at the Department of Veterans Affairs, referring to a psychological operation, in this case intended to intimidate federal workers. “It’s a form of harassment. But there’s no one to complain to because no one knows exactly where it’s coming from or who’s behind it.”  

The president’s Saturday morning post spurred Musk to confer with his deputies at the Department of Government Efficiency and develop the hastily written email, according to a White House official. The email was sent by the Office of Personnel Management, now staffed at senior levels by Musk’s deputies. They told agency employees that they intended to use artificial intelligence to analyze the responses and develop reports about further changes to the federal workforce, according to an OPM official familiar with their comments.

Two senior administration officials said that the haphazard nature of Musk’s directive rankled some in the West Wing, as concerns grow that the billionaire’s authority is encroaching on the power of Cabinet secretaries.

Trump, for his part, publicly backed Musk’s effort. “I thought it was great because we have people that don’t show up to work and nobody even knows if they work for the government,” the president told reporters during an appearance Monday with French President Emmanuel Macron. “What he’s doing is saying, ‘Are you actually working?’ And then if you don’t answer, you’re sort of semi-fired or you’re fired, because a lot of people are not answering because they don’t even exist.”

White House Press Secretary Karoline Leavitt also defended the actions: “This was the president’s direction to Elon, and it is being carried out as planned,” she said. “Everyone at the White House knew very well that it was coming.”

The same can’t be said for other parts of the federal government, where agency heads were caught off guard and many recipients mistook the email for phishing. Employees on leave or on vacation feared that they would lose their job. At HHS, department leadership was given just a five-minute warning before the email went out, a senior official at the Centers for Disease Control and Prevention told his staff on Monday, according to people familiar with his account. HHS did not respond to a request for comment.

Some of the agencies that advised employees to respond to Musk’s email sought to justify the request in guidance issued on Monday. John W. York, a senior counselor to Treasury Secretary Scott Bessent, told employees, “The OPM message reflects an effort to increase accountability by the federal workforce, just as there is in the private sector. Given the voluminous and extremely important work that Treasury staff perform on a daily basis, we expect that compliance will not be difficult or time-consuming.”

Around 5 p.m. Monday, HHS finally issued new guidance affirming that a reply was not mandatory but warning employees who did detail their professional activities to protect sensitive data. “Assume that what you write will be read by malign foreign actors and tailor your response accordingly,” the guidance stated.

Meanwhile, there were signs that OPM was working to make parts of the Musk directive permanent, at least within the agency. In an email to employees Monday evening, OPM’s acting director wrote that he had asked the chief human capital officer to “operationalize this exercise” so that employees continue to “submit weekly accomplishment bullets.”

In certain corners of the federal government, workers made light of the Musk request. One Pentagon official told a colleague that his reply would include time spent on Fox News, Truth Social, and X—more reliable sources of information about the terms of his employment than his own bosses.

“Who are we taking orders from?” the Pentagon official said. “No one really knows.”