Dateline | May 03, 2013
>> look at this place now. so ordinary. with its pharmacy, its grocery store, carefully tended parking places, so alike the suburban strip malls from bismarck to bakersfield. but that night, that cold night a heat gathered here. sweet, terrifying, doomed.
>> for the longest time, i couldn't go anywhere. because i'm thinking everybody is looking at me.
>> this is the story of two married couples , how the advice they can offer others now that it's too late for them.
>> i think if i could tell them anything, it would be put your family first.
>> but, of course, that's not what happened. and this parking lot , there will be a body here before we're done.
>> oh, my god! oh, my god!
>> careful when you stir the hot pot of desire. the place is meridian, ohio. a little above boise in the foothills of majestic rockies. the perfect place, the end of the rainbow. 2006 , and luck was on their side. they just moved from southern california , and they were happy. they were fulfilled at work. they had two beautiful children. they had everything they ever wanted. they were rob and kandi hall. one of those charmed couple who's had fallen in love at first sight in this case, first sight meant admiring each other in the gym.
>> we went out that weekend and then we never stopped.
>> what was it about that relationship? what was it about him that was so good?
>> we just connected instantly.
>> by the time rob and kandi moved to idaho, they had been together for years. had two teenage daughters. rob landed excellent job as a computer specialist at the ada county sheriff's office. specializing in vehicle locators inside squad cars .
>> he loved every minute of his job.
>> and as if it was a sign, kandi 's career as a paralegal took off too a natural, could and did sell her confidence and skills to anybody who walked in the door.
>> it didn't hurt that she was pretty.
>> no, it didn't and her coworker idolized her. you became close?
>> reporter: we became very close. she was just like a mother to me.
>> it was all just about perfect. and then who knows why these things happen exactly. they just do. and no onemagined, why would they, how this thing was going to end. but eight months into his new job, rob started traveling for work. nothing unusual about that, of course. but soon, he seemed to be staying away from home a little longer than he really had to. started snapping at her too, kandi said, about little things . not like the old rob at all. so at this point you began to suspect something?
>> reporter: yeah, i start thinking what is going on? why are you acting like this?
>> and then one night after a light flight in from california, rob lay down beside his wife in bed, and it all came tumbling out.
>> reporter: he just started to cry. and he said i'm having an affair. and i laid my head on his chest and i said, rob, please, just fix it.
>> you didn't get upset, didn't yell, scream, cry, do anything?
>> reporter: that's what shocked him. you know, the typical response is get the hell out.
>> throw the clothes out the window.
>> reporter: oh, no. the last person on this planet you would think to have an affair would be robert.
>> but, of course, it was devastating, crippling. every day she went to work, and every day sofia saw her friend turn herself inside out and seemed to wither.
>> reporter: i watched her go through misery, sobbing in her hands daily and try to figure out what this woman had that she didn't.
>> did she still love him?
>> reporter: yes. dearly.
>> and wanted the marriage to continue in spite of the affair?
>> reporter: yes, she did. she didn't want to believe in her head she felt something in this woman that wasn't in kandi .
>> he felt bad about it, agreed to go through counseling with kandi . but -- after he confessed and you said fix it, he didn't.
>> reporter: he didn't know what he wanted.
>> come on. he wanted to keep going with the affair, that's what he wanted.
>> reporter: i for sure told him to stop.
>> stop right now or i'll stamp my foot and hold my breath. and he kept doing it.
>> reporter: it was my fault. he a void because of me. that's what i thought.
>> what do you think the void might have been?
>> reporter: i just was boring.
>> boring old kandi hall, rejected, apparently unlovable, and nearly 40. and then one day at work, kandi was introduced to a recent law school graduate, looking to staff his new office. a boyishly handsome, smart as a whip, cocky young lawyer . his name was emmett corrigan.
>> reporter: my friend, she said, emmett, have you got to met kandi . i mean, she's just as passionate and aggressive as you are,nd she would be great for you.
>> and something suddenly lifted in kandi hall. by the time those words had left her