Catwoman #13 (HERE BE SPOILERS!)

I'm not really sure what I'm supposed to make of this issue.  It's pretty clearly Joker who stole Selina's best friend's mementos and taunted her with them, though I only really know that because I know that this issue is part of "Death of the Family."  However, I'm not sure if the main story in this issue is part of a long-running one in this title, since I don't read it.  It involves Selina getting hired to move giant chess pieces that someone is using in a game being played throughout Gotham.  Honestly, it didn't make much sense to me, so I'm not sure if that someone is Joker and the author is being intentionally vague or if it's a plot that I would recognize if I read the title.  Given that "Batgirl" #13 had little to do with "Death of the Family," it seems possible that I'm just missing a lot here.  Either way, I can't say that this issue really added a lot to my understanding of Catwoman or "Death of the Family," so I think it's totally skippable if you're only here for the latter.