"I begged him not to bring any more there to suffer the hell I went through," Knight said.
But it wasn't long before Knight learned that she wasn't the only captive.
In 2003, Berry joined her inside the house. At first, she said, they rarely saw each other.
"When we did, it was like a quick hug and 'bye,' because he wouldn't let us stay in the same room for that long," she said.
When they were in separate rooms, Knight said, she would blare her television if she saw Berry's mother on air, to make sure Berry knew to watch. And when she saw Berry, Knight said, she tried to comfort her.
"Sometimes she would cry, and I'd tell her everything would be OK, and that one day we'll get home," Knight told McGraw. "We just have to, you know, wait it out."
Castro's main 'punching bag'
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.
In the interview with McGraw, Knight said she once watched Castro kill a beloved dog by breaking its neck. She said she was kept nearly naked in a frigid room with windows boarded up. And she said Castro once punched her in the stomach with a barbell when he learned she was pregnant.
"I fell to the floor. ... He said, 'Tomorrow it'd better be gone. That's all he said,'" Knight recalled. "Then when I did miscarry, he blamed me. He said that I hated him, that I killed his kid, and he punched me in the face, saying that it was all my fault."
A troubled past
During Knight's time in captivity, her case got less media attention than the disappearances of Berry and DeJesus, whose family members posted fliers and held candlelight vigils for them.
Knight's grandmother, Deborah Knight, told The Plain Dealer in May that the family had concluded that Michelle had left of her own accord because she was angry that she had lost custody of her then-2-year-old son. That conclusion was supported by police and social workers, she told the newspaper.
Knight told McGraw that her son was taken away after her mother's boyfriend abused him.
"And then they tried to say that I never protected him, and I did," she said. "I did all I could do."
She was still trying to do all she could on the day when she was abducted in 2002, Knight said. She told McGraw she got lost on the way to a meeting with social services to discuss her son's custody. That's when she stopped at the dollar store to ask for directions, she said, and when Castro offered her a ride.
In the interview, Knight also gave a glimpse into what she described as a troubled childhood before her abduction, which she said was why she didn't want to see her mother after she was released.
"I wished my mother wasn't my mother. ... I wasn't allowed out. I wasn't allowed to have friends. She made sure I was dumber than a doorknob," she said.
In response, her mother, Barbara Knight, issued a statement to the "Dr. Phil" show.
"Michelle, my daughter, has been the victim of long-term and profound and unspeakable torture. Her point of view has been altered by that monster and what he did to her," the statement said. "What I have heard that she said about me breaks my heart. That is because what she now believes, while not true, increases her pain. I love my daughter. I always have and always will. I pray that someday she will heal enough to know that again."