I'm going to talk a bit more about my adapting The Wonderful Wizard of Oz as a film...
When you're writing a script like this, it's not enough to just transcribe the book into script form. The book's story works well on film, but this would offer you nothing that reading the book wouldn't.
It came to mind today where I got my inspiration on how to handle the melting of the Witch. Most writers would turn to a fantasy or maybe a comedy for this. Maybe they'd even try to make the scene reminiscent of the MGM movie, or some piece of artwork. (One animated adaptation made the Witch's final moments resemble "The Scream" by Edvard Munch.)
I saw the moment as breaking down into two parts, the visuals and the feeling.
The visuals, I didn't want her turning into water or just sinking into the floor (or a toilet...). Instead, I had the idea that the Witch's body is extremely dry, and only her magic is keeping her alive. When she is struck with water, her body soaks up the moisture like a sponge, but it's too much for her structure, so she loses control of the magic that is holding her together. As such, her body begins to sag and stretch before turning into this gelatinous goo that would be quite a nasty mess to clean up afterward. (Poor Dorothy.)
The feeling of the moment came from an not very-Ozzy source. Dorothy, is, of course, guilty of a murder (unless you want to say the Witch is still alive in this shape, but then, she's defenseless and unable to communicate), albeit unintentional. In which case, when she realizes what she's done, she's very distraught over it, mixed with only a little sense of victory.
Instead of turning to Oz or a fantasy, I turned to the movie Heavenly Creatures, Peter Jackson's retelling of the true story of the Parker-Hulme murder. The feeling that that movie's closing scene gave was perfect for this scene in Oz. (Two sobbing girls beating a woman to death, a woman who happened to be the mother of one of the girls.)
Yeah... Inspiration can come from a variety of sources.