. >> reporter: the second highest ranking member of nxivm is a woman named nancy salzman. former members say she is known as "prefect." >> so keith and nancy, vanguard and prefect. >> reporter: at the heart of nxivm training is something called intensives, which former members say are like group therapy, running as long as 14 hours a day for up to 16 days. edmondson says she attended her first in 2005 when she was 27. >> 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. i could communicate better with people. >> reporter: that sounds fantastic. >> yeah, it was great. >> reporter: classes are invitation only and they are not cheap. a five-day "intensive" will run you $3,000. the 16-day is $7,500. in promotional videos and materials it claims more than 16,000 people world wide have taken nxivm courses. many testify to its effectiveness. >> i learned through the tools that there was a different way. >> reporter: sarah was recruited into the group by filmmaker mark vicente. what was it that was so compelling to