For over a decade NXIVM, the costly self-help course that eventually gave way to an alleged sex-trafficking cult, has flourished. Leader Keith Raniere created a celebrity-attracting business that doubled as his own personal hunting ground, as “slaves” within a sub-sorority of the cult were allegedly groomed for Raniere and ordered to engage in sex acts with him.

Sarah Edmondson, an ex-DOS member who went public with the sorority’s perverse practice of branding its initiates, wants to see Raniere, who is currently in prison awaiting trial, brought to justice. “Keith has been able to continue on with these types of abuses because nobody talks about it,” Edmondson insists during the premiere episode of A&E’s new series Cults and Extreme Belief. And while lengthy legal documents pertaining to Keith Raniere and his alleged second-in-command, former Smallville actress Allison Mack, are publicly available, Edmondson’s testimony as a 12-year member of NXIVM offers invaluable insight into the cult and Keith Raniere—a “sociopathic, narcissistic, nut job.”

The episode, which premieres on May 28, juxtaposes photos of Raniere with NXIVM promotional videos and sage comments from cult experts. But the show is really about Edmondson, an incredibly brave woman who sees her mission to shed light on NXIVM as an act of penance.

She says she was first introduced to NXIVM through Mark Vicente, another high profile defector. At the time, Edmondson recalls, Vicente told her about “the smartest man in the world”: Keith Raniere. Edmondson, an actress who says that she wasn’t having the “impact” she had hoped to, was an easy sell. She paid over $2,000 for an upcoming five-day course in Vancouver, where she was introduced to the “rules and rituals” of NXIVM—one of which was calling Raniere “Vanguard.”

“We call Keith Raniere ‘Vanguard’ because vanguard means the leader of a philosophical movement,” Edmondson explains. “All of it is preempted with, there’s going to be things that happen in this module that will make you uncomfortable. And you will feel the urge to bolt, and that’s totally normal…it means that you’re doing it right.”

“ They paddled each other, videotaped it, naked, and sent that to Lauren who sent it to her master, who now we know is Keith. ” — Sarah Edmondson

Edmondson became a believer—“I remember feeling like I’d been given a book of secrets”—and even partnered up with Vicente to open a center in Vancouver. Her subsequent status as a top NXIVM recruiter is why she feels so guilty—guilty enough to spend a “year of hell” trying to out Raniere at any cost. “I brought so many people into NXIVM,” she explains.

Of course, at the time, Edmondson genuinely thought she was offering a great opportunity—the chance to take part in a program that had changed her life for the better. And, as Edmondson recalls, she wasn’t the only one who thought that NXIVM was the real deal. “Richard Branson took our course, the Dalai Lama’s endorsing us,” she lists off.

(After publication, a representative for Branson told The Daily Beast that the Virgin Group founder has never taken a NXIVM course and has never heard of Keith Raniere.)

“Allison Mack, who’s an actress, is part of NXIVM,” Edmondson continued. But of course, the biggest star was Raniere himself. Edmondson remembers, “We were told that Keith is a genius with an IQ of 240, who was speaking in full sentences at the age of one, that he was a concert pianist, he was the east coast judo champion at 11, he earned degrees in mathematics, biology, and physics.”

Vicente, who helped make the Keith Raniere videos that have since gone viral, remembers the beginnings of his NXIVM disillusionment: “Where it got really problematic for me is that some of the people that Keith was mentoring, like Allison Mack, began just enrolling all of these girls, pretty young girls. Very consistent.”

“I started to have suspicions about Keith and his relationship with women,” Edmondson continues.

She was a part of Jness, a workshop within NXIVM designed specifically for women. In retrospect, Edmondson considers Jness’s teachings to be an example of Raniere’s twisted ways. “He’s telling us we need to look at our indoctrination, how we’re raised as women is very different than how men are raised, and that indoctrination is disabling for us…women are designed to be monogamous, and men are designed to be polyamorous. Men are designed to spread their seed, to populate the world, and we’re designed to be loyal to our man and be subservient. In the process of understanding our indoctrination he is slipping in a new indoctrination,” she claims.

Lauren Salzman, a close friend who acted as both Edmondson’s maid of honor and the officiant at her wedding, was the one who recruited her to DOS. The secret sorority was structured through master-slave relationships between women; Edmondson and her fellow recruits had no idea that Raniere was the one calling the shots.

There were strict rules. If your “master” texted you, you had to respond within sixty seconds. The first time that she and her fellow “slaves” failed to respond at a certain time, Edmondson recalls, “Lauren told us that there were going to be big consequences for her from her master. And we asked what, and she said that she was going to be paddled…and she told us that she was going to be put into a cage.” The women decided to opt for the same consequences, only worse: “They paddled each other, videotaped it, naked, and sent that to Lauren who sent it to her master, who now we know is Keith.” Edmondson avoided this fate, since there weren’t any other DOS group members in Vancouver.

Edmondson was also ordered to “collateralize” her life. Legal docs have elaborated on this NXIVM practice, which included “sexually explicit photographs; videos made to look candid in which the prospective slaves told damning stories (true or untrue) about themselves, close friends and/or family members; and letters making damaging accusations (true or untrue) against friends and family members and assigning the rights to certain assets.”

Having handed over her collateral, Edmondson says she was now eligible for the initiation ceremony that was later described in The New York Times’ 2017 NXIVM exposé. Edmondson, who had been expecting to receive a tattoo, quickly found out that she was going to be branded. She watched another naked woman undergo the painful procedure, knowing that she couldn’t risk walking out: “It was not an option for me because she had all this shit on me.”

“I don’t think people can imagine what it’s like to have your skin seared open by a hot cauterizing iron for 40 or 45 minutes,” she says. “It was the most excruciating pain I’ve ever felt in my life.”

In the end, it wasn’t the branding but the brand itself, a combination of Keith Raniere and Allison Mack’s initials, that gave Edmondson the courage to finally cut ties. She went to Mark Vicente, who was “Fucking horrified…They burnt her with his fucking initials. They did that to someone I brought in, who trusted me. And then I thought, how many other girls are in this position?” Vicente recalls urging Edmondson to “get out” immediately: “I told her, this is fucking trafficking.”

Edmondson and her husband, Anthony Ames, left NXIVM in June 2017, and she’s been a whistleblower ever since. “Keith really thought that this whole collateral thing would just stop people from talking. And it didn’t,” says Edmondson. “I’m not going to stop talking about it until Keith is held responsible.”

While Edmondson, who didn’t know the full extent of Raniere’s alleged crimes at the time, feels incredibly vindicated by Raniere’s arrest, she says that she’s still afraid of the cult leader behind bars. “I’ve seen how people will follow any order that he puts out,” she explains.

Still, she concedes, “I believe that Keith’s arrest is the beginning of the end for NXIVM. I would say that he messed with the wrong person, and that for such a ‘brilliant’ man he made a big mistake. He really underestimated me.”