Definition: Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title
Input: I have a couple of questions about the ending of the horribly disturbing Oldboy (2003). Why does the antagonist "Puppet Master" kill himself in the elevator? Was he so consumed by revenge that he had nothing left after he carried out his purpose? The realization that after all he had done to exact revenge, it didn't ease the pain of his first (and most likely only) love dying? I can kind of understand those but it seems a bit single-minded of him and/or simple, maybe. Also, did the final hypnosis work on the protagonist? Or does he still know that she is his daughter?
Output:
Explanation of the ending of "Oldboy"