NEW YORK (AP) — In an often wrenching memoir, Jaycee Dugard recounts in unsparing detail the rapes, isolation and heartbreak she endured during 18 years as a kidnap victim twice impregnated by her captor.

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Titled “A Stolen Life,” the memoir is officially scheduled to go on sale next week. The Associated Press purchased a copy Thursday.

Dugard, now 31, was kidnapped from South Lake Tahoe, Calif., in 1991, when she was 11, then sexually abused and held captive for 18 years by Phillip and Nancy Garrido. She gave birth to two daughters by Phillip Garrido. The couple pleaded guilty and received lengthy prison sentences earlier this year: 431 years to life for Phillip Garrido and 36 years to life for his wife.

Dugard writes that she decided to publish the memoir for two reasons: to provide a precise account of the ordeals inflicted on her by the Garridos, and in hopes that her story might be of help to people facing difficult situations of their own. She said her goal was to inspire people to speak out when they see something amiss around them, that they “can endure tough situations and survive,” she writes.

She describes how she was abducted as she walked up a hill toward her school bus stop in June 1991 — paralyzed by a stun gun wielded by a man who then bundled her into his car and covered her with a blanket. Before long, she was forced to shower naked with Garrido and placed in handcuffs in a locked room.

She writes of how little she knew about sex when Garrido began raping her, about a week after the abduction. The word “rape” was not even in her vocabulary. But even if she had been worldly, she writes, no amount of preparation could have helped her understand “why another human being would do what he did.”

The rapes continued on a frequent basis — with Garrido often getting high on drugs before indulging in his fantasies, some of which he videotaped.

Yet Dugard writes that she found herself starting to feel deeply dependent on Garrido, who initially was her only human contact. He told her she should be amenable to having sex with him because it meant he wouldn’t have to molest anyone else. She writes that she had no choice. She also talked about her dependency on Garrido in her grand jury testimony.

Eventually, Dugard says in her grand jury testimony and in the book, that he gives her a kitten, which she names Tigger. He later takes the cat away because he doesn’t like the smell. Later, Garrido introduces Dugard to his wife, Nancy. Dugard recalls being glad to have another human contact, yet is ambivalent about the relationship. For her 12th birthday, Dugard gets a Barbie doll from Nancy.

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In the spring of 1994, Dugard realizes she’s pregnant. She recalls being stunned, yet — as she feels the baby moving inside her — vows that she will never give the child away. She recounts the painful delivery in her bedroom, giving birth to a baby girl on Aug. 18, 1994.

She is 14, she writes, and is “very, very scared.”

The rapes subsided after the girl’s birth, but still occurred sometimes when Garrido took drugs, Dugard writes, and she became pregnant again. The second daughter was born on Nov. 13, 1997.

In her grand jury testimony and in the book, she says that one of the reasons she stayed with Garrido, rather than trying to escape, was because she wanted to be sure her two daughters were safe with her. She was afraid of the “outside world,” she writes.

Eventually, Garrido allowed Dugard and the two little girls to leave his compound. Dugard was given a new first name, Allissa, to use in the earshot of other people.

The Garridos’ secret unraveled in 2009. They were arrested a day after Phillip Garrido had brought his entire family to a meeting with his parole officer, and had identified Dugard and her daughters as his nieces.

When a female officer asked Dugard for her name, she was too nervous and shaken to say it aloud, instead writing on a piece of paper, “JAYCEELEEDUGARD.” In the book, she describes the moment as “breaking an evil spell.”

The book, published by Simon & Schuster, concludes on a reflective note. Dugard writes about her therapy sessions, analyzes her own behavior during her years with the Garridos, and wishes the best for her daughters in the future.

Her eldest daughter, identified only as “A” in the book, is now in high school, and Dugard describes how that milestone stirred up her own grief at what she had missed out on.

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Dugard writes that she tries hard to appreciate each day, but is “still afraid it will be taken away.”