A Wicked Return to Oz

So I have been listening to the Wicked album and wanted to write based of a Wicked FanFic I had read the link to their story will be below. They left it unfinished, so it was going to bug me if someone didn't come up with an ending. Granted I am not done yet, but still.
Synopsis: Dorothy couldn't stop thinking about the Wicked Witch she had melted back in Oz. So she finds a way back a seeks out Glinda for answers. Glinda warns her about what she will see and takes Dorothy on a trip into her past with the Wicked Witch.
Note:
-Later in the story I continue to say Ga-linda instead of Glinda, so that you and I would know which Glinda is speaking. Galinda=Past and Glinda=Present.
-Again I wanted to continue their story because they did such a great job, that I at least wanted to give it an ending.

Link to the story that I based mine off of:
https://www.fanfiction.net/s/5813920/1/Getting-to-know-the-Wicked-Witch-of-the-West