(CNN) -- Six months after she was freed from the "house of horrors" where Ariel Castro held her captive for 11 years, Cleveland kidnapping victim Michelle Knight is speaking out.
In an exclusive interview with Dr. Phil McGraw scheduled to air Tuesday and Wednesday, Knight describes a moment when Castro trapped her in a room and tied her up with an orange extension cord.
"I was tied up like a fish," she said, "an ornament on the wall." In excerpts of the interview posted on the show's YouTube channel, Knight says Castro taped her mouth shut with duct tape. She tells McGraw she once picked a lock to try to escape, drawing an ominous warning from Castro: "Now you're gonna be punished."
Knight, Amanda Berry and Gina DeJesus were freed from Castro's Cleveland home in May, drawing national attention to the horrific case.
The dramatic rescue came after neighbors heard Berry's cries and broke down a door.
In August, Castro was sentenced to life in prison plus 1,000 years after he pleaded guilty to 937 counts, including murder and kidnapping. He committed suicide in his prison cell in September. Knight, 32, was 21 years old when she was reported missing. Before their rescue, Knight's disappearance generated less publicity and attention than the kidnappings of Berry and DeJesus, and a level of mystery still surrounds her case.
But since their rescue, Knight hasn't shied away from speaking out.
"After 11 years, I am finally be heard, and it's liberating," she said in a powerful statement at Castro's sentencing describing the abuse she endured.
"You took 11 years of my life away, and I have got it back. I spent 11 years in hell, and now your hell is just beginning," she told Castro. "I will overcome all this that happened, but you will face hell for eternity."
When crews demolished the 1,400-square-foot house where Castro held them captive, Knight was there, handing out yellow balloons to onlookers.
She said she was at the demolition site in part to remind relatives of abducted children that all is not necessarily lost. "I want the people out there to know -- including the mothers -- that they can have strength, they can have hope, and their child will come back," she said.
Since their release, accounts have depicted Knight as someone who cared for the other victims during their captivity while also enduring great suffering herself.
A family friend of one of the victims said this year that Castro used Knight as his main "punching bag."
The friend said Castro hit Knight with a variety of objects, including hand weights. She has suffered vision loss, joint and muscle damage, and other problems from her time in captivity. According to an initial incident report obtained by CNN, Knight said she became pregnant at least five times while in Castro's home.
When that happened, she told investigators, Castro "starved her for at least two weeks, then he repeatedly punched her in the stomach until she miscarried."
Knight said Castro ordered her to deliver Berry's child, according to a police source familiar with the investigation.
"What's most incredible here is that this girl who knows nothing about childbirth was able to deliver a baby that is now a healthy 6-year-old," a police source said.