Elizabeth Smart was tragically kidnapped from her Salt Lake City home when she was only 14-years-old. Almost 15 years later, Smart, now 29, is telling all on the horrors she faced while being held by her captors for nine months. In Smart’s upcoming documentary Elizabeth Smart: The Autobiography, she describes how her captor, Brian David Mitchell, got away with stealing her in the middle of the night while she was sound asleep in her bed. Smart woke up to the threatening voice of Mitchell who had a blade held up to her neck. “If you scream or you yell I’ll kill your family or I’ll kill you,” Smart recalled Mitchell telling her. SEE ALSO: ”Impregnated by stepbrother, raped multiple times by Catholic priest…”- Grace, 19, Shares Heartwrenching Story She believed that some of her family had already been dead and she thought to herself “either go with him or die.” As Mitchell, who was 49-years-old at the time, now 64, made his escape with Smart, she recalls they were close to having a run-in with a police car that drove by. Smart remembers Mitchell saying, “If this work is true, God, then let this car pass.” “He was kidnapping me and he was mentioning God, it didn’t make sense,” Smart said. After running for a while, Smart stopped abruptly and told Mitchell if he was planning to rape and kill her to do it right then in the open field they were in. “In my mind I was thinking ‘I want my parents to know what happened to me. I wanted them to find me even if it was just my body,’” Smart explained. Smart eventually made it to an isolated part of the woods where she would meet Mitchells wife, Wanda Barzee. Within moments, Barzee had summoned her to the tent and forced Smart to take all of her clothes off despite initially refusing several times. SEE ALSO: “I’ve never been raped because I don’t dress like a prostitute …” – Twitter User Brags Barzee then made her put on a robe. The tent door unzipped and in came Emmanuel” — the name Mitchell called himself — Smart said. “He knelt down next to me and started to speak and I just remember thinking, ‘no just go away, just leave me alone.’ I calmed down enough to hear the last sentence. He told me that I was now ‘sealed to him as his wife before God and his angels as his witnesses and that could never be undone,’ Smart recalled. “I just remember being filled with horror, I remember just screaming out ‘NO!’ and he looked at me and said ‘if you ever scream out like that again, I will kill you.’” Smart said Mitchell repeatedly told her ‘it’s time for us to consummate’ their marriage.” Smart told him that she hadn’t even had her period yet, to which Mitchell yelled out from inside the tent to his wife asking if it was still okay to have sex with Smart. Barzee responded with ‘it’s fine.’” Smart believed if she could turn herself on her stomach, he wouldn’t be able to rape her. “He just pulled up the robe and raped me. I was devastated. and I remember just thinking how on earth did this happen to me, why did this happen to me.” Mitchell would rape her repeatedly everyday for nine months, strapping a metal chain around her ankles so she wouldn’t escape. Smart would starve for days at a time, and she believed that she would die. “There was nothing I could do about it. I mean couldn’t run away, I couldn’t fight him off, I had already tried — he was bigger, he was stronger, there was nothing that I could do until it was done. He was the master and i was the slave, that was the real lesson of the day.” SEE ALSO: ”My 8-Year-Old Daughter Was Raped & Killed by Someone I Call ‘Cousin’ | A Father’s Heartbreaking Story On March 12, 2003, nine months after she was kidnapped, police were able to spot Smart with two other people on the side of the road as they were walking in Salt Lake City. Barzee was sentenced to 15 years in prison for assisted kidnapping. Mitchell was found guilty on kidnapping and sexual assault charges and is currently serving a life sentence in prison. Smart has this advice for parents from her experience: Make sure your child knows that they are loved unconditionally, and make sure your child knows what unconditionally means. Make sure that your child understands that no one has the right to hurt them or scare them in any way. It doesn’t matter what that person may be: family, friend, religious leader, community leader, it doesn’t matter. Should anyone hurt your child or threaten them in anyway, they need to tell you. She also adviced: “Practice screaming, encourage your kids to fight back, there is a place and a time when it’s not only acceptable it’s encouraged.” Smart has since become a campaigner against pornography and abuse.