Transcript for Where the secretive organization NXIVM case stands
For Hollywood actress Allison Mack, this was judgment day. Any comment? How do you think you were misguided by raniere? Reporter: Once a star on the show "Smallville." That explains the theory. Reporter: On Monday, the 36-year-old pled guilty two counts of racketeering, which included forced labor. She faces up to 40 years in prison. She broke down in tears, forcing the judge to ask if she needed a second to compose herself. Reporter: Against a mysterious self-help group called nxivm. Many of its members charged with numerous crimes, including conspiracy to commit forced labor, sex trafficking. I soon realized think were not nice people. The fact that Allison Mack pled guilty to so few charges and was facing so many certainly indicates that she's likely cooperating with prosecutors. Reporter: On the surface, nxivm, also known as executive success programs, described itself as a self-help group. It's a program that is designed for people to identify what it is they want to do in their lives and how they can do it the best way possible. Reporter: Allison Mack was attracted to the goals of the group. Here she is appearing in a video testimony. I had something on the surface that seemed like a pretty good life. Reporter: The group's leader was this man, Keith raniere. Members referred to him as vanguard. So one would say authenticity is being as you are. Reporter: Raniere's words literally moved Mack to tears. I don't know why, that makes me want to cry. It's beautiful. But why, why do you think that's -- So emotional for me? Yes. I don't know, I think it's something that I, I want it, authenticity. Reporter: Sara Edmondson was a former member of nxivm. She told my former colleague, Elizabeth vargas that Mack was a favorite of the management. She had a huge following, I think they thought this would be another big fish to catch. His movement was to recruit women for dos. And during her statement on Monday, she admitted to recruiting women to this group and under the guise it was female empowerment. Reporter: Sara Edmondson says she fell for that ploy. One night in March of 2017 she says she and four other women were summoned to a house outside of Albany, New York. They willingly participated in a strange initiation ritual, led by a woman who told everyone to take off their clothes and put on a blindfold. Led us in blindfolded, and sat us in a semi-circle, buck-naked. No clothes on a sheepskin rug. Reporter: Edmondson told authorities she thought they were going to get tattoos. Instead she says they found out they were all going to be branded. What was that like? It was worse than childbirth. Imagine a hot laser graged across your flesh without painkiller for 30 minutes. Keith's initials on one side and am for Allison Mack but I didn't sigh that at the time. Reporter: This shocking scene is the last place Edmundson expected to show up. She's a wife and mother and has a successful career. But her life changed after she crossed paths with the so-called self-help group and its charismatic leader raniere. I'm an interesting person, a controversial person. But most importantly, I'm an unconventional person. I was told that he was one of the smartest men in the world and just an incredible man. Reporter: At the heart of nxivm training was something called intensive, which former members describe as group therapy. It ran as long as 14 hours a day and up to 16 days. Edmondson says she attended her first one in 2005. The price tag over $2,000. I left my five-day, my initial training as if a veil had been lifted, and I could see things more clearly in my life. Reporter: According to former members, nxivm even had its own lingo and it involved practices such as chanting. A special handshake, even bowing. To vanguard. Thank you, vanguard. Reporter: Former members like mark vin sente say anyone unwilling to go along with the rituals was scorned. If you question raniere, . How dare you, don't you realize you owe everything to him? Reporter: Sara says it went further. Women were taught to be subservient to men and he practiced what he preached by having what amounts to a harem of women. It was like having a normal boyfriend, except you didn't know when you'd see him next. He'd go out with another woman. Reporter: They'd travel all over the world to celebrate his birthday, an annual celebration known as vanguard week. Wishing vanguard a happy I loved v-week. I missed my best friend's wedding. It makes me emotional. I missed her wedding. Reporter: Edmondson was in the group for 12 years, rising through the ranks. She became close to Lauren Salsman. She was Edmundson's maid of honor. She's like my therapist and also above me. Reporter: In March of 2017, after their years together in nxivm, Edmondson says Salsman approached her about a new and mysterious opportunity. Life changing but top secret. Reporter: But Edmundson claims Salsman demanded highly-compromising collateral first. In response she and others ended up providing nude photos of themselves. I did it because I trusted her. Reporter: Only then did she gain entry. The first step is making a vow of obedience to her as her being the master and me being the slave. Slave? Did you object? I objected every stage of the way. And she said it's a metaphor, like guru, disciple. The women on the table screamed out in pain, twisted and turned and yelled. And the woman I was with, holding her legs down, we looked at each other and wept. Why didn't you lit go and run out of there and run out naked. It didn't seem like a choice at the time. Reporter: Can you stand up and explain where the brand is? It's right here under my underwear line. Reporter: Edmundson believes raniere should be held accountable because she saw a text come in as she held Lauren's phone filming the branding. He said how is it going. Reporter: He was also being investigated for extortion, wire fraud and identity theft among other possible crimes. And then, in March of 2018. Hey! Reporter: His empire came tumbling down when he was busted by the federales in mex quo. His hideout was a $10,000 a week villa in Puerto Vallarta shared with the women. This video was shot and shared by followers and leaked online. He was brought back to new York to face federal charges, including sex trafficking. The next month, Allison Mack was Were you involved in a sex cult? Reporter: And a few months later, more arrests followed, including that of Lauren Salsman, the woman whom Sara says recruited her into that secret group. She pled guilty to racketeering and racketeering conspiracy. If you're Keith raniere, you've got to be nervous about the fact that these other people are pleading guilty. We don't know for certain that they're cooperating. But that would be really bad news for Keith raniere. Reporter: Raniere is currently behind bars. He has pled not guilty to all of the charges against him. Raniere's criminal trial is set to start next month.
This transcript has been automatically generated and may not be 100% accurate.