The plot revolves around a largely psychological battle between Batman and his longtime foe the Joker , who has escaped from Arkham Asylum . Batman paid a visit to Arkham Asylum, and specifically to the Joker's cell. He then tells the Clown Prince of Crime that he's been thinking of their battles, more specifically how they're most likely going to end: One of them is most likely going to kill the other, whether it be Joker killing Batman, or Batman killing Joker, that most likely it may happen either sooner or later, and wonders if Joker himself is aware of that. However, he then realizes the man in the cell is not actually the Joker, and demands to know where he is. The Joker intends to drive Gotham City Police Commissioner James Gordon insane to prove that the most upstanding citizen is capable of going mad after having "one bad day". As part of his plan, the Joker managed to scam the owner of a run-down amusement park into giving him control, also poisoning him in the process when shaking hands on the deal, revealing that the park was actually Joker's since an hour beforehand thanks to his minions forcing his business partner to grant Joker ownership. Along the way, the Joker has flashbacks to his early life, gradually explaining his possible origin.
That is all perfectly true, but as applied to hunting rifles and cartridges, terms such as "killing power," "knockdown power," and "stopping power" are generally used pretty much interchangeably. A game animal must be both killed and prevented from traveling any great distance (stopped, if you will) if it is to become dinner or a trophy.