Fans learned Jessica Joan’s haunting story about being “groomed into a sex slave” by NXIVM in How I Escaped My Cult. The Freeform docuseries’ executive producer, David Karabinas, reveals the “No. 1 red flag” to look out for in an exclusive interview with In Touch, noting there will be some telltale signs.

“To me, it’s isolation. Any group that wants to isolate you from your friends and family, to me, that’s a giant flag,” David exclusively tells In Touch. “If they’re legitimate and they’re above board, whatever they’re teaching you, whatever they’re saying to you, they shouldn’t be afraid of you explaining that to other people, and they shouldn’t want to remove you from other people.”

David says the best way to remain safe in a group setting is to “bring your friends [and] bring your family” and “go home when you’re done.”

Joan was a cult victim featured on How I Escaped My Cult. She was raised by her grandmother after her drug-addicted parents lost custody, and she was sexually abused by a male adult while in middle school. Following a 2016 move to L.A. in her mid-20s to pursue acting, she accepted an invite to a personal development seminar hosted by NXIVM, which presented itself as a self-help organization with a charismatic leader, Keith Raniere.

Desperate to heal and impressed by women she met there — including Dynasty actress Catherine Oxenberg’s daughter India, 33, and Smallville star Allison Mack (actresses from Hawaii Five-O and Battlestar Galactica were also members) — she joined. Soon, she was offered a “mentorship opportunity” in a secret subset of the group called The Vow.

What happened next only deepened the trauma she was so desperate to escape. Jessica was ordered to hand over three pieces of collateral detrimental to her reputation — others submitted nude photos, sex tapes or private family information — so there could be “an exchange of trust,” she was told.

Months later, she learned what was really going on: “I was being groomed to be a sex slave,” she explains in How I Escaped My Cult, a docuseries now airing on Freeform and Hulu in which she and others detail how they eventually left 10 oppressive groups, including House of Yahweh, La Luz del Mundo, Word of Life and others. “NXIVM is a good example of where, in the beginning, it all seemed probably all right,” David Karabinas tells In Touch, explaining how vulnerable people are often lured into these organizations with promises of mentorship, a better life, safety or even salvation. “Then it just devolves into something that’s just bonkers.”

Women in The Vow were isolated, ordered to restrict calories — Keith, 64, wanted them slim — and some were even ritualistically branded with his initials. In 2017, after Allison, 42, instructed Jessica to “seduce” Keith, claiming it would rid her of her childhood sexual abuse issues, Jessica plotted her escape. She took photos confirming the existence of the forced “blackmail” submissions, fled to Hawaii and told federal investigators everything she knew.

Keith was arrested in 2018 and later sentenced to 120 years in prison on sex trafficking and racketeering charges. Allison received a three-year sentence for her role in the abuse. “One thing that’s common throughout a lot of these cults is sexual assault and sex crimes,” David tells In Touch.

I Escaped A Cult episodes air weekly on Thursdays on Freeform, and the entire season is currently available on Hulu.