Michelle Knight, one of the three women who was held captive in the Cleveland home of Ariel Castro for a decade, remembers the exact moment she realized something was deeply wrong on the day she was kidnapped.

It was August 2002, and she had just accepted a ride from Castro, who had offered to drive her to a court appointment regarding her then-two-year-old son. But instead of taking her to court, he drove her to his home.

Knight, who was just 21 at the time, said that it took her some time to realize something was wrong.

"It didn't start coming to me until I got closer to the house, when he locked the gate and then I got into the house," she said. "After I got up the stairs, it was over."

Knight is opening up about the 11 years she spent in captivity in her new book "Finding Me: A Decade of Darkness, a Life Reclaimed."

In a Canadian TV exclusive, she shared details with CTV's Canada AM about the physical and sexual abuse she and Amanda Berry and Gina DeJesus, the two other girls held captive, suffered at the hands of their tormenter.

The beatings and rapes started soon after their abductions. Castro would put a helmet and chains on Knight’s head and neck to stop her from screaming during the assaults, she said.

During the 4,000 days she spent in his home, she said she became pregnant five different times. Each time Castro would force her to end the pregnancy, sometimes assaulting her so that she would miscarry.

"He would kick me, he would punch me, he would jump on my stomach, he would knock me down the stairs," she said. "He would literally take a barbell and hit me right in the stomach."

In addition to the physical and sexual abuse the girls endured, Castro would also play mind games with them, she said. He would tell the girls that he had left the door unlocked and threaten to hang them if they tried to escape.

He would also tell Knight that if she tried to leave he'd harm the other two girls, which made her think twice about leaving. "I don't like other people getting hurt, so I tend not to do things that would get others hurt," she said.

The girls were eventually freed, after Berry managed to escape and get help on May 6, 2013.

Knight said that her eventual liberation, which came after police arrived at Castro’s house, was an "amazing" but also traumatizing experience.

She said that when officers eventually came into the home, she and DeJesus were hiding because they thought it was a burglar instead.

"I didn't even really think that we were going home," she said.

Castro was arrested and later pleaded guilty to more than 900 counts of rape, kidnapping and aggravated murder. He was sentenced to life in prison without the chance of parole plus 1,000 years. In September 2013, he committed suicide while in prison.

Now, one year after she was freed, Knight says she's been able to find a way to forgive Castro.

"It was very difficult. It was a roller (coaster) of emotions, but you tend to put it behind you because you tend to forgive the person slowly but surely," she said.

"I would want somebody to forgive me for all the bad things that I've done in life, and trust me there were a lot of bad things. Even though it may have been small things, I would still want somebody to forgive me because it doesn't make him any less than a human."

'I question it all the time'

There are many troubling details that have emerged about the girls' case that Knight still struggles to understand.

After they were freed, it became clear that there were several different instances when other people had seen one or all of the girls.

In one case, Knight said Castro had brought his grandson to the house, and the boy started screaming when he saw the girls. The boy’s mother later came to the house to investigate, but Castro had locked the girls in the basement to keep them out of sight.

Another time, Knight said Castro took her out into his backyard with barely any clothes on and a neighbour saw them. She was too afraid to call out for help, but was certain the neighbour would call the police. However, the neighbour did nothing.

She said a lot of people didn’t see the signs, which included the constantly locked doors and closed windows in Castro’s home.

"It's kind of confusing, especially with the cops and the people that said they (saw) me in the backyard,” she said. “I’m just wondering why? Why didn't you come back? … It's very confusing that they didn't see the signs."

Knight said this is one of the reasons why she is now speaking out. She wants people who think they may have seen something odd or peculiar not to hesitate in calling the police.

"If they see signs like that, even though you look stupid, call the cops. You might be saving more than one girl," she said.

She said that it is also her son, who was adopted by another family, that keeps her motivated to continue working and sharing her story. She noted that while in captivity, she would often have conversations with her son in her mind to stay sane.

Knight has decided that her son should stay with his adopted family, but admits that she still misses him every day.

"It's very difficult, especially since Mother's Day came up and all I thought about was him. But I know that he's in a good place, and I'm very proud of him and I love him so much," she said.