There's a book and play called "Wicked". It's "The Wizard of Oz", told from the viewpoint of the Wicked Witch of the West.
The copyright for "The Wizard of Oz" has expired. That book and play don't violate anyone's copyright.
Unfortunately, Congress has repeatedly retroactively extended copyright law. For most things written in the 20th century, the copyright has not expired. Most copyrights are owned by large corporations.
Copyright law has been used for censorship. It's been used to prevent people from publishing books that retell popular stories.
Here are examples of books that were quashed by copyright law:
- the wind done gone (was actually published)
- 60 Years Later: Coming Through the Rye ("Catcher in the Rye" unauthorized sequel)
- an unauthorized Harry Potter encyclopedia ("Harry Potter Lexicon)
- Sherlock Holmes
- A Christmas Carol
- Mark Twain (notably, removing the "n-word")
Many popular stories are now part of everyone's shared culture. It's wrong for them to still be copyrighted.
"Wicked" is an example of a clever story. It's only possible because the "Wizard of Oz" copyright has expired.