Hanna Gabriele is a very troubled woman. She is suicidal, and cutting and burning herself just to get through the day. Her employer tells her she needs to get help. Therapy has failed her in the past, but Hanna decides to give it one more try, and calls Rachel Gunner, a therapist she called at random. It was the right call to make.

In Beyond These Walls: The True Story of a Lost Child's Journey to a Whole Life, written from the dual perspective of therapist and client, Rachel discovers that Hanna has Disassociative Identity Disorder, or DID. Formerly called Multiple Personality Disorder, Hanna has 26 distinct personalities within her. Hanna's childhood was filled with gruesome torture, including starvation, sleep deprivation, beatings, and rape at the hands of her mother, her step-father, and their friends. Perhaps most shamefully, Hanna was forced to participate in the ritual murder of a young boy.

To escape these abuses, her personality fractured, starting around the age two (the youngest personality within). Each personality could only handle so much abuse. Other personalities came along to be the protectors. All the personalities were children. Through years of intensive therapy, Rachel was able to do what no other psychologist had been able to do: make Hanna a whole human being.

Some of the personalities within Hanna include: Randy, an eight-year-old male who was Rachel's greatest ally. He gave her hints on how to deal with all the other personalities, reminding Rachel that they really were just children. Tigger, the youngest in "the system" at two years old, could not talk. She only screamed and chewed her arm. Mikhail, 18, took care of the "grown-up" duties, like holding down a job and paying the bills. "The Killers" were a small "gang" of young children who wanted nothing more than to let "the body" die. The authors included a helpful list of all Hanna's personalities, their ages and sexes, and what is known about them.

Hanna and Rachel author alternating chapters of Beyond These Walls. This offers unique insight into Hanna's condition. Rachel describes her methods and how they differ from therapists before her. She describes the challenges she faced in trying to gain the trust of "the system" and convince them not to die, to stop burning and cutting, to start eating and sleeping regularly, and teach them that they were not to blame for the abuse. Hanna describes what was going on with the different personalities, giving an "insider account." Unlike many memoirs, this one isn't whiny or have a "woe is me" aspect woven throughout it. It is matter-of-fact without losing emotion.