09/07/2016 AT 10:00 AM EDT  Nearly 40 years ago, Colleen Stan made a fateful decision.  On May 19, 1977, she got into a car with Cameron and Janice Hooker, a seemingly nice young couple with a baby, while hitchhiking to a friend's birthday party from her Eugene, Oregon home.  She never made it to that party.  About 30 minutes after she got into their car, Cameron pulled off onto a dirt road, held a knife to her throat and threatened to kill her. He bound her, gagged her and placed a homemade wooden box over her head.  "I thought I was going to die," Stan, now 59, and living in northern California, tells PEOPLE in an exclusive interview in this week's issue, on newsstands Friday.  Instead, over the next seven years, she found herself living a nightmare some would say was worse than death. The Hookers took her to their home in Red Bluff, California, and imprisoned her in a box underneath their waterbed for 23 out of 24 hours a day. She was brought out only to be beaten, raped and tortured.  Patrick Dempsey on the cover of PEOPLE  That first night in captivity was one of the most difficult, she says. She was chained up inside a crate-like box in a sitting position (he later built her one that was more like a coffin).  Later, Cameron told her he was a member of a group called "The Company," which would hunt her down and kill her if she escaped, and made her sign a slave contract from the group.  Stan escaped in August 1984 with the help of Janice, who later testified against Cameron in court in exchange for immunity. Cameron was found guilty of kidnapping and sexual assault and sentenced to 104 years in prison.  Addison Timlin plays Stan in the Lifetime movie "Girl in the Box"  Darren Goldstein / DSG Photo  This Saturday, at 8 p.m. ET, Lifetime will air a movie about Stan's ordeal titled  She says she kept her sanity while in the box by focusing on all her happy memories of her family and friends.  "I learned I could go anywhere in my mind," she says. "You just remove yourself from the real situation going on and you go somewhere else. You go somewhere pleasant, around people you love. Whatever makes you happy."  Today, Stan is married for the fourth time and raising her grandson, who turns 2 at the end of September. Despite all that she's been through, Stan says she has had a wonderful life since her escape and is grateful to be alive.  "Your life is just kinda in limbo when you're in captivity, and once you get that freedom back and you have that choice again, it's just like the gates open," she says. "And you just run for it."
Colleen Stan opens up to PEOPLE about her ordeal and story of survival – and the new Lifetime movie about her life