I had never heard of the Afghan concept of 'bacha posh', where a family with only daughters could decide to dress one of the girls as a boy and have her/him permitted to behave as a boy; attending school with other boys and being excused the household chores like a boy would be, able to go out and do the shopping, escort sisters to school and work outside the home. Apparently everyone would know that the bacha posh is a girl but would treat them as a boy; teachers, neighbours, and other children, would all go along with the charade. Once she reaches puberty, she would revert to being female, which must have been emotionally painful after all the freedoms she would have enjoyed.
In The Pearl That Broke its Shell, Rahima becomes Rahim and enjoys life as a boy until her opium-chewing father marries her off at thirteen. Her new husband is a warlord who offers a sizable sum, and promises a continuous supply of 'medicine' to Rahima's father. At the same time her older sisters, Shahla and Parwin are also sold into the same family. They had hoped that they would see each other regularly but this proved impossible and each had to adjust to a hard life as the youngest wife. As such, they were given all the worst chores and found themselves on the receiving end of the jealousy of the other women. The mothers-in-law were particularly nasty.
Slotted in-between this modern day narrative, is the story of Rahima's great-great grandmother, Shekiba, who, in the early twentieth century found herself dressing as a man to guard the harem of the king. This story is told by Rahima's crippled aunt who has certain freedoms because she never married, and she is able to visit the girls occasionally.
Certainly an excellent premise for a novel. Unfortunately it didn't quite work for me. The narrative didn't flow and I was bothered when it alternated between first and third person for no obvious reason. A lot of information was gathered by overhearing conversations, which, while feasible, seemed a bit weak.
However, this is a debut novel, and in spite of my reservations, I would not hesitate to read another book by this author in the future.