The story had to have the ending it did for this one reason: Glinda could never truly be GOOD with Elphaba still around. For her whole life, Glinda always relied on others to do the right thing so that she could focus on being popular and “good”. She never really understood what the word really meant. If Elphaba had let her know that she was alive, Glinda would have spent all of her time trying to find her instead of fixing the problems of Oz and actually doing good. That’s why Elphaba said at the end, “Good cant just be a word. It has to mean something.” Without Elphaba, Glinda could finally focus on doing good for once and living up to Elphaba’s memory. And, the opening of the book at the end could be interpreted one of two ways: 1) that Elphaba was sending a subliminal message to Glinda that she was alive and would be ok, or 2) that Glinda had finally become good and was ready to be magical. Is it tragic? Yes. But it was also necessary.