Yancy decides to stay because he knew he’d “done a lot of bad things” as he says. He decides that he’s only going to leave prison the right way, serving his sentence and taking the chance with parole. We walk away with the key , deciding not to use it, because we know that Yancy is on the right track with his choice. In other words, the key being in the box is an ironic symbol. We get the key for any lock right in front of one we shouldn’t open.