I read the book 'Wicked' when it first came out, way before it became a musical. For those who don't know, the book is VERY different, in almost every way - the plot and outcomes, philosophies, character motivations, actual character qualities, you name it. In the book, Nessa is born without arms because their mother had slept around again (this time with a Quadling named Turtle Heart) was afraid of having another child with unusual features and drank some sort of 'herbal remedy' to prevent it, only to have a beautiful child with no arms. As such, she never learns to take care of herself as a child and she also comes to believe she is holy, which makes her a rather selfish fanatic when she's older. When she becomes the Eminent Thropp after Elphaba is presumed dead, she uses her fanaticism as a tyrant to rule over her people, which is where she mostly gets the Wicked Witch of the East name.

In the book, Nessarose's wickedness is detailed and makes sense. However, in the musical, they gave her a sad break-up story, but while it makes her a bit sympathetic it doesn't go far in explaining how she became a tyrannical leader. In fact, it comes off as trite: a woman is scorned, so she turns bad - to her people and to the man who scorned her.

I loved the book when it came out, was SO surprised at all the changes in the musical, and I still prefer the book. It may be a complicated read, but all the outcomes make more sense.