Dateline | November 07, 2013
>>> on a frigid december morning in 2008 in a tiny picturesque down on thebacks of the delaware.
>> the whole house is on fire.
>> a deadly blaze burned a small country house to the ground. and left behind in the ashes more secrets, love gone wrong, illicit affairs, friends turning against each other. it would take years to unravel the mystery of that fire, haunting this town. and those who loved the couple who once lived in that house , paul and catherine novak.
>>> the novaks had both grown up as city kids . paul was a new york city paramedic, a job that seemed the perfect fit .
>> i wanted to be that person that would show up that would help my parents and help my sister if she was in a car accident or something like that.
>> but he also saw the dark side of city life , a little too close to home .
>> i would do shootings and stabbings two blocks away from my apartment and i always thought to myself, i would never raise a child in this area.
>> so in 2002 , paul and his wife catherine went house hunting in narrowsburg, new york, a small hamlet tucked between the cat skill and pocono mountains . they didn't look for long.
>> it was the big red house as she called it. she would talk about the big red house all the time.
>> catherine 's brother michael and sister-in-law joanne said she worked hard to make the big red house a home.
>> growing up, we lived in apartments. you know, this was a space of her own.
>> she was thrilled to have five acres or ten acres of property and she loved it there.
>> the perfect place for the perfectly matched couple. they seemed meant for each other right from the start.
>> i liked her from the first moment i met her. she was very effervescent and very funny and opinionated and i really liked that in her.
>> so you really saw into the future the first time you saw her?
>> yes. we ended up getting married, i think seven months later.
>> two years after that, their first child, natalie , was born.
>> very special.
>> catherine 's mom, christina, was ever the proud grandmother.
>> natalie looks so much like her mom. so much like her mom.
>> what was it like the first time you laid eyes on your new daughter?
>> natalie , wow, it was like falling in love like a thousand times more than you have with any other person. natalie is just -- she's a part of me.
>> four years later, along came nicholas.
>> she was in her glory and to have a boy and a girl, which was good. things were all coming together.
>> she got directly engaged in the community, in the church. she taught sunday school. she became a girl scout leader, the school board . she did many, many things.
>> and she did almost all of it by herself. paul was still working as a paramedic in new york city . more than 100 miles away .
>> that's a big commitment. this is pretty far from the city.
>> it's a two-hour drive drive. i was making the new york city money but living up here. the sacrifice was i couldn't be home every night.
>> and that they soon discovered can be tough on a marriage.
>> we went to counseling for about a year and she just felt that she never got a break from being a full-time mom.
>> but they were both committed to making their marriage work. on their tenth wedding anniversary , valentine's day, paul surprised catherine with a ceremony to renew their vows.
>> i'm not a church going type. for me to do that is a big thing. i planned a little, you know, couple of days get away and she was really taken by surprise by that. and things were good for a couple of months after that.
>> it wasn't enough. the glow of that get away faded and life became routine again. soon paul 's eyes wandered to a much younger woman, someone from work. they had an affair and paul moved out leaving catherine and the kids alone in the house .
>> she was beside herself. she was absolutely hysterical.
>> catherine 's good friend and neighbor, sue muller, remembered when the marriage ended.
>> she couldn't even get breath, she was sobbing so hard.
>>> but catherine 's family who considered her the eternal optimist, watched her move on with her life, pouring all her love and attention into her children.
>> she was very focused on that, very engaged in their lives, did everything with them.
>> sounds like that's what was important in her life anyway.
>> she was working at her children's school and had been on a few dates. catherine was creating a life without paul . then in december 2008 , sometime in the early morning hours, somewhere in her house a fire started.
>> a house is totally on fire, it's on fire.
>> when firefighters arrived, the big red house was a wall of flames. they had no idea if anyone was still inside.
>> does anyone live there?
>> yes, yes. there are kids.
>> do you know if they're out of the house ?
>> i don't know.
>> neighbors knew paul wasn't there. he was living in an apartment three hours away with his new girlfriend. that morning he got a call from catherine 's pastor.
>> picked it up and it was pastor phyllis. she goes where are the kids? i'm like they're with me. what's going on? she's like the house is on fire.
>> firefighters worked for hours dousing the flames. when sue muller arrived, the fire was still raging. she stood vigil for hours waiting to hear news of her friend.
>> all of a sudden, the firefighters were concentrated in one area, looking down into the basement and the local funeral home was there with the body bag . i saw them bring the body bag into the basement.
>> in the destruction and muck of the basement, under massive pieces of what had been the house , firefighters found the remains of the family dog and, to their horror, the body of 41-year-old catherine novak.
>> oh, no, oh, no. it can't be. i think it takes a while to grasp that death is forever.
>> what did you think when you heard that news?
>> i was a blank. a complete blank. what on earth am i going to tell these children? how am i going to tell them? she was a great mom. i didn't know how i was going to be able to fill that void.
>> the autopsy report said she was killed when heavy debris fell on her. catherine 's death was officiallily ruled accidental.
>> she lived a courageous life. she knew what she wanted, she went after it. she was very bold in the things she did.
>> a tragic end to a life that held so much promise. but as you've probably guessed, the story didn't end there. for investigators, it was just the beginning. not everyone