She was trapped between a door and a window.
Strange, really, because it seemed like that should be impossible. The door was unlocked, all she had to do was turn the handle and she would put an end to this dilemma. Easy enough. The window could not be opened like the door, but it was glass and could be broken using any excessive amount of force. It would cause much more commotion and mess than simply opening the door, but it was still a feasible means of escape. No one should be able to be trapped by two exits, of all things. But that was what she had, and she was very soundly stuck in between them.
Two exits. That was the problem.
The door seemed to glow, softly, almost enticingly. Well, she knew what lay behind it. Everything from her wildest dreams could be hers if she opened the door, everything she had ever wanted was within her grasp. All she had to do was reach out that last few inches and it could be hers. But the window loomed over her shoulder, calling her back. The land outside of the glass pane was foggy, it's inhabitants unpredictable. There would most likely be great danger if she went that way. But it was impossible to tell just how hard her journey would be if she took that route. There may also lie great reward through the window. A different, perhaps even more satisfying reward, but a reward all the same.
In reality, rewards didn't matter so much to her. She looked down at her feet and saw the two paths leading to each of her options. The one leading to the window shone of pure gold and silver bricks. The window hung ominously above it, as mysterious as ever, but that only seemed to enhance its appeal, now. The path leading to the window was noble, morally correct, right. The path leading to the door shone, too, but it was the lustrous, alluring shine of emeralds. But the emeralds' sparkling seemed too wrong, too gaudy, as if they were trying so very hard to get her through that doorway. She looked closer, and she could see that that path was paved with lies and deceit. And then it became clear that those stones were fake.
So, on one side of her glowed the door that held everything, but was built on false promises and wrongs. On the other side there was the window that held a bleak view, but was built on truth and justice. There was no more debating. She knew what she had to do.
Elphaba grabbed a broom and smashed right through the window.