Garden of Shadows (Dollanganger, #5) by V.C. Andrews

Garden of Shadows is the prequel to Flowers in the Attic. I strongly recommend that you read it last as it is book 5 and will have more of a punch after having read the Dollanganger saga. 

This book gives insight into Olivia and how circumstances changed her into the person we read about in Flowers in the Attic. Olivia wasn't initially a cruel person. She was naive and fell for the handsome Malcom Foxworth. What she thought would be a marriage turned into a disaster.

Initially Olivia is a likable character and while her circumstances don't excuse who she becomes her story is sad. She has a different expectation of marriage than Malcom does. Malcom is cruel and treats her as though she is less than a person. Olivia experiences loses in a variety of ways and each loss chips away at her turning her into the shadow version of Malcom. 

Readers are given a lot of background information and answers to some questions from the previous four books. Be prepared for an emotional journey.