(No explanation, but Peter knows Jinx comes in and comes out of his place like an outdoor cat, so, no surprises either? A piece of paper is taped to his wall, a puzzling and overly complicated map of the subway station paths until there's a 'X' marking a location. Big challenging puzzle, it makes zero freaking sense unless, well, you can see it how Jinx sees it when she wants to be a brat.
cryptic message on his wall
Good luck, Peter, bless your heart.)