Sarah Carlson spent seven years analyzing the attack plans of Middle Eastern terrorist groups for the CIA. Now the agency is trying to stop Carlson from writing a book about one tumultuous aspect of her service.

Carlson is set to file a lawsuit demanding the agency permit her to go forward with a book that touches upon her time as an analyst for the CIA’s highly secretive Counterterrorism Center. The bureau within the CIA that ensures former officials don’t publish official secrets, the Publications Review Board, already cleared her manuscript twice.

But in November, two years after Carlson first submitted her manuscript, the CIA board told her that “the entire manuscript reveals classified information,” according to a copy of her imminent lawsuit provided to The Daily Beast. It’s even trying to stop Carlson from publishing her intended book title.

The book, Carlson told The Daily Beast, doesn’t reveal a scandal. She doesn’t “say anything negative about the CIA,” she said. “It’s very focused on a specific year and what happened there during a dangerous environment, a crisis and what we did in response.”

About all she can say, now that the agency has revoked its green light, is that it was about a “devolving situation” in North Africa. “I really do want to protect classified information,” Carlson said, and she wrote the book “so hopefully we could avoid a repeat of what happened, avoid the risk of war and intervention outside the major war zones.”

To Carlson’s lawyer, Mark Zaid, who has spent 25 years representing intelligence officers in disputes with their employers, it’s a “frustratingly typical and avoidable” episode from a CIA that remains fundamentally uncomfortable with its alumni’s rights to speak out.

Carlson and Zaid claim that the agency has used official secrecy to violate her First Amendment rights. To do so, they allege, the agency has “improperly classified information that is, in fact, unclassified.” The declaration that Carlson’s book contains classified material puts her at risk of prosecution if she publishes it.

From April 2008 to September 2015, Carlson, now 38 years old, worked at the CIA’s Counterterrorism Center, analyzing terrorist groups’ plans and patterns of attack outside their Mideast and North African home courts. She was based both out of the agency’s Virginia headquarters and abroad, including in the North African country she can’t name. Before joining the agency, Carlson worked as a counterterrorism analyst for the Defense Intelligence Agency, a job that brought her to Baghdad during the occupation. The daughter of a Presbyterian minister, she went into intelligence work soon after 9/11, while her three brothers joined the military. Her faith, she said, helped sustain her in troubling times like the incident at the center of her book.

The agency’s position prevents her from discussing what that incident actually was, as well as where and when it specifically occurred. Carlson would not discuss it with The Daily Beast, saying only that it received some press coverage at the time.

While Carlson has maintained a relatively low profile since leaving the agency in 2015, she has published analytic articles at security-focused websites like War On The Rocks and Real Clear Defense. Those pieces—which, she said, were cleared by the CIA at the time—focus on Libya. One of them refers to a “harrowing, all-out, 26-hour U.S. evacuation” of personnel from Libya in July 2014, an event well-covered at the time if little remembered now that followed a spasm of militia violence in the capitol, Tripoli. Another confirms her role at the U.S. Mission in Tripoli and said she “helped conduct the full-scale U.S. evacuation.”

Carlson said she began writing her book soon after the incident it details, to help her cope and make sense of it, and because she had some concern she might be called to testify about it. (She never was.) Her lawsuit indicates that she submitted her manuscript in October 2015, a month after she left the CIA.

According to her lawsuit, the Publications Review Board gave Carlson’s book the all-clear on two separate occasions. The first time was in November 2016, a year after she first submitted it. Following some revisions, Carlson provided the board with another look at her updated manuscript in January 2017, and got a second round of approval in February of that year.

In an added complication, Carlson had asked the CIA to change her official cover status. Though she had gotten aspects of her resume approved in 2015 by the same publication board, without a change in cover status, Carlson’s employment prospects were sharply restricted. She got the new status in September 2017, one that provided her with more leeway to describe her time at the CIA. She now works in an emergency-management related field in the Pacific Northwest.

Ironically, making her more public creates a disincentive for clearing her book, since now her public status would permit observers to trace back her particular experiences abroad and connect them to the CIA. “Now we’re revealing that person is our person in that country on that day,” is how Zaid used a hypothetical example to illustrate the conundrum. (Notwithstanding Zaid’s own high-level security clearance, he has no access, he said, to any classified aspect of her story.)

That same month, after consulting with her new literary agent, Carlson made changes to the book. She described them as cosmetic: more material about her personal background, and, in her lawsuit’s phrase, “her thoughts about a high-profile attack that occurred in her assigned country prior to her arrival.” Carlson estimated that the non-personal additions amounted to about a page of new material. She gave the new manuscript back to the publication board soon after.

By November, the Publication Review Board had made a wholesale change. They informed her, in a November 15 letter, that “the entire manuscript” revealed classified material, according to the lawsuit, and vetoed publication “in any form.”

The CIA declined comment on Carlson’s story.

The Publication Review Board is notoriously mercurial.

“The process has been painless for some people, but extremely aggravating and frustrating for others,” said Steve Aftergood, an intelligence and classification expert with the Federation of American Scientists. “It’s not, as one might imagine, that senior officials are always given a free ride and underlings are forced to jump through hoops. Even senior officials have been known to tangle with the PRB. It’s been somewhat unpredictable – some people sail through and others spend years, even to the point of cancelling the book project. It’s certainly opaque and often inconsistent and unpredictable.”

Carlson’s story is a case in point. Adding to her frustration is two years of correspondence with the agency review board that she said openly reference material from the book it now says is classified – speaking to the retroactive secrecy she claims the agency has pursued. She has not shared that correspondence with The Daily Beast or even her attorney Zaid.

“I think I have a unique perspective as a woman, an analyst and a former CIA officer in these kinds of dangerous environments,” Carlson said. But with her book in limbo, and with a looming lawsuit representing her best shot at escaping it, the public is a long way from getting Carlson’s perspective at all.

“Part of the problem is I had it all cleared and now it’s not,” Carlson said, “so it’s hard to know now what’s acceptable to say and what’s not.”