Given scene/plot descriptions from movies or TV shows, and given a specific question about the scene, summarize the question into a title
Example: At the beginning of the movie Gangs of New York, Priest Vallon tells his son not to wipe the blood of the blade after he's cut himself shaving, saying "The blood stays on the blade". I've watched the movie multiple times, but can never find what the meaning behind that phrase is. Anyone able to shed some light on this?
Example solution: What's the meaning behind the phrase "The blood stays on the blade"?
Example explanation: A person gives a detailed description about a scene from the movie Gangs of New York and asks the meaning of a said phase in the scene. The question is summarized as What's the meaning behind the phrase "The blood stays on the blade"? for easy indexing the next time someone searches for a similar phrase

Problem: I clearly don't understand the motivation for President snow of the Hunger Games: Mockingjay and the leader of the Capitol (Capital) to hurt Katniss Everdeen by using Peeta on screen and getting Peeta to say all these things about a ceasefire but when the rescue team from District 13 go to the Capitol and rescue some remaining tributes from the Hunger Games that have been held ransom, they are helped out by some supporters in the Capital itself. But when they get Peeta back to 13, he attacks Katnis by strangling her. Why would President Snow just let Peeta be captured by District 13 rescuers and let 13 take him? Also to add: why would Peeta have saved 13 from the bombing from the Capital and basically saves them, when he is rescued he attacks her? what is going on here?
Solution: Why did President Snow want to use Peeta to kill Katniss?