She thanked the woman who sold her as a sex slave at 13

Yeonmi Park, a North Korean defector who later became an activist for refugees, was 13 and recovering from surgery for what doctors thought was appendicitis, performed without painkillers. Her hospital had no X-ray machine and often no power, and the staff used one needle for every patient. Park says being treated could be more dangerous than going without treatment. Her older sister, 16, had already escaped with a friend and left a note by Park's bed telling her to follow a woman who could get her out. That woman was a trafficker.

The woman sold Park and her mother into China as sexual slaves in 2007. Park says she is grateful to the woman for doing it, because if she had not been sold that day she would be dead.

She sold her five daughters too, some as young as 7 and 10, to China as well. She was later executed for trafficking. Park still refuses to condemn her.

"That was the only way for her to save her children," Park says.

Park arrived in China at the end of March. By October, six months later, she felt she had lived an eternity. One day there felt like one year, and every night she went to bed grateful for one thing, that she had survived another day without being captured.

She remembers going numb. She describes looking at herself as if she had left her body, watching a girl being assaulted and struggling to survive, and feeling nothing for her. She calls feeling nothing a bigger torture than fear or sadness. She says she began to heal only years later, after having her son.

Park says, "we tell ourselves stories in order to live." She used the line as the title of her book.

She thinks of the trafficker as the person who changed her life by selling her. "If she didn't sell me that day, I would be dead right now."