two others named in the suit have already done so. but still, a mystery endures about a woman who vanished on a warm, september night while the rest of the world was looking the other way. that's all for this edition of "dateline." i'm craig melvin. thanks for watching.

and really worked hard to get to we ultimately got her degree anw became a professional. >> then michelle even at an early age always seemed confident about getting what she wanted. she was just 16 when she started dating marty.

marty was a couple of years older, worldly, bright, friendly, had big plans.ld he wanted to be an astronaut.d he went to the air force academy. ♪ she was 20 when she married him at the academy's famous chapel outside colorado springs. >> marty, you may kiss your bride. >> this was back in 1991 when marty was all she ever wanted. long before she talked to that psychologist, agreed to record for the record her thoughts she'd have to overcome and her days with marty, of course. >> we did everything together. he treated me really well. i thought we had the perfect relationship. we were best friends. >> he was the dashing young officer back then. she his lovely bride. the future she imagined an

endless honeymoon in which marty's air force career would take them to exotic destinations all around the world. she just didn't imagine that world would be unromantic air force outposts in oklahoma and alabama and florida, to finally fayetteville, north carolina. they came here in 1999. marty was captain theer by them, flew one of those huge c-130 cargo planes. all that time alone, not so easy on a marriage. as she revealed during those tape recorded interviews with psychologist dr. debby leighton. >> michelle talked about a few problems in the marriage. primarily growing apart over the years. marty was away for extended periods of time.s she had a hard time with that. it was getting difficult for her. she was lonely. et >> sometimes he was gone for months and when he finally did come home, military families have come to know that adjustment period all too well.

they bickered, they argued about her housekeeping, his job, about having children. he wanted them, she didn't. she was worried she'd be stuck raising them by herself in a town where she was already miserable and lonely. >> fayetteville, loserville and had nobody to hang out with, nobody i could pick up the phone and call. >> that actually is about the time it started. harmless really. just a few key strokes. see what might happen. goes on all the time these days on the internet. sexy brunette seeks rendezvous man. and before long, her internet inquiry got a response. from him. the name was john, john diamond. >> john loves women. john was a lady's man. john always had girlfriends. >> so debby, john kid's sister, could certainly see her brother responding to a solicitation like michelle's. he >> my brother has a great personality.

he's an attractive guy and, you know, his personality makes him that much more attractive.s >> then a few days after meeting online, they met in person at a local restaurant. >> he was charming, he was funny. movies and music and things we talked about. >> he was an army sergeant, trained at ft. bragg, trained as a sniper, highly decorated. had been in the service since he was 18.e >> by all counts, he was a good soldier, but he was a playboy, himself. he had been married once beforeo and had a child from his first e marriage and he left the first wife and married and they had a son together. >> michelle didn't know that john was still married. but maybe it didn't matter. at least not then. she loved the sex. the attention. the excitement.th >> he was very sensitive, he was very affectionate, he was very e adoring. yes, felt great.

>> i think it was just the sex. that's what he was obsessed with. he was smitten with having sex with her. >> for michelle, well, it was more lust than love. >> she felt that the affair did not take away from the fact that she loved marty. she said he was the love of her life and that she never loved john diamond. >> marty, he was in the dark, o course. when michelle told them their marriage was in crisis and they needed to see a counselor -- w >> he wouldn't agree with counseling and i moved out. he was shocked.ul >> michelle got her own place and spent much of that steamy fayetteville summer with john diamond.t >> he was so attentive. he would rub my feet for five hours if i want him to.ub >> diamond was nuts about michelle, never met anyone like her before. >> she challenged him ways he'd never been challenged before. >> paul wolverton is a reporter with the "fayetteville observer."

>> she was strong and intelligent and exciting for him. >> but was he enough for her? apparently not because after three months on her own, michelle went back to marty. >> she felt that the marriage could survive, despite everything that has happened. that they could make it. >> so john and michelle's six-month affair seemed to be off.