President Donald Trump isn’t the only one in the White House who could be caught in a compromising position by James Comey’s secret memos. The president’s chief of staff is worried he could be soon in the crosshairs, as well.

Comey, the former FBI director who was fired earlier this month by Trump, took detailed notes of his interactions with the president and senior Trump administration officials in order to properly document conversations that were on the verge of improper.

Three White House officials told The Daily Beast that Chief of Staff Reince Priebus has privately expressed worry about a possible Comey memo specifically involving one of their reported chats, and how it might play in the press and to investigators.

“Nervous laughter,” one official succinctly characterized Priebus’ demeanor in the midst of recent revelations.

In late February—long before Trump fired Comey over the “this Russia thing”—Priebus had reportedly already acted on the president’s behalf in trying to use the FBI to quash the Trump-Russia news.

According to CNN, Priebus asked Comey and his then-top deputy, Andrew McCabe, on Feb. 15 to refute news reports about conversations between Trump campaign staff and Russian government officials. Comey and McCabe reportedly refused. The White House denied the story at the time.

That conversation happened the day after President Trump reportedly asked Comey to dial back the bureau’s investigation of retired Lt. Gen. Michael Flynn, Trump’s ousted, and preferred, national security adviser. As first reported by The New York Times, the former FBI director subsequently documented that conversation in a memo that leaked last week.

This week, The Washington Post reported Trump had been unsuccessful in persuading two of the most senior U.S. intelligence officials to publicly deny the existence of evidence linking his 2016 campaign to Russian efforts to undermine the American political process. Trump’s request was made after Comey informed the House Intelligence Committee that the FBI was investigating.

Senior Trump aides recounted to The Daily Beast the shockwaves and “sustained panic,” as one official described it, that news of the initial Comey memo sent through the administration and Trump’s political inner circle. Along with the chaos and continued frustrations that came with attempting to manage the fallout, there was an immediate unease expressed by senior staffers, including Priebus, that more damning memos could be revealed in the coming weeks, if not days.

These officials spoke on the condition of anonymity so as to speak freely.

“Reince is worried about leaks, since elements in the FBI seem determined to wage this war in the press,” a White House staffer said. “Initially the concern was about public perception—trying to get Russia out of the headlines—but it’s looking more like this will be a drawn out legal battle too, even if [Trump associates are] eventually exonerated.”

That attitude reflects a “growing realization of this thing’s staying power,” the staffer said, referring to the larger controversy involving alleged Russian election-meddling and administration attempts to limit fallout from the investigation. There’s “a sense that if there’s damning information out there it’s going to come out one way or another—someone leaks it to the Times, or the president just blurts it out in an interview.”

Priebus and the White House did not respond to multiple requests for comment on this story.

Any anxiety on Priebus’ part, however, would appear to be well-justified. According to one former general counsel of a large law-enforcement organization who is familiar with Comey, the fired FBI director took judicious notes on likely every conversation he had with anyone from the White House—and he almost certainly wrote a memo about the Feb. 15 conversation with Priebus.

Priebus’ private conversation with Comey could have violated longstanding FBI policy barring officials from discussing its cases with the White House, according to Politico. Comey certainly knew about this policy—meaning it’s all but certain he would have written a memo about such a controversial conversation.

The former general counsel described Comey’s memos as a “time bomb,” and noted that Comey took handwritten notes, and kept hard copies of all his memos in his office at FBI headquarters, and also kept digital copies.

Over the past few months, Comey had a host of meetings—not just with Trump and Priebus—that could have provided fodder for private memos.

In the first week of January, Comey joined then-Director of National Intelligence James Clapper, NSA Director Adm. Mike Rogers, and CIA Director John Brennan for an intelligence briefing with the president. Comey pulled Trump aside after the briefing to tell him one-on-one about the dossier that allegedly contained “kompromat” on him, according to CNN.

On Jan. 22, two days after inauguration , Comey shook hands with Trump and spoke with him in the Blue Room of the White House during the president’s National Law Enforcement and First Responders reception. Getty Images has pictures of the encounter. Vice President Mike Pence and other law enforcement leaders were also present for the reception.

Naturally, Comey has also had multiple meetings with Attorney General Jeff Sessions, who is above him in the Justice Department’s chain of command. Before his firing, Comey answered to Deputy Attorney General Rod Rosenstein, who answers to Sessions. They appeared together publicly on Feb. 9, the day Sessions was sworn in, and on April 18 for a meeting on transnational organized crime.

Sessions was a key player in the White House’s move to fire Comey, as has been widely reported. His involvement in the decision drew sharp criticism, as Sessions announced in February that he would recuse himself from all matters related to the Russia investigation—an investigation Comey was overseeing until President Trump canned him.

In the coming weeks, Comey is set to publicly testify on Capitol Hill. Until then, Trump and his inner circle are left to wonder what Comey and his allies have in store for the president next.

“We’re waiting for the other shoe to drop, quite frankly,” one White House official told The Daily Beast. “We’re all waiting.”