A walk in the swamp

My latest book from the library is Blood Shot by Sara Paretsky which came out in 2012. I've enjoyed her mystery books about a female PI named V.I. Warshawski and this unabridged version is a long 11 CDs. On the way home from church this morning I finished disk #6 and was hooked enough into the story to bring the rest of the CD's into the house and listen to them while I fixed lunch. I kept on listening, switching CD's as each finished. When I started playing CD #9, the voice of the narrator changed and I was in the middle of a shoot out between characters I hadn't heard of. I stopped the player and looked at the CD. Yes - it said Blood Shot on the front next to a big number 9. Skipped ahead a bit but this was definately not the same story. Pulled out the CD again and compared it to the previous one.  While they both had Blood Shot on the front,  #9's stated it was written in 2010 by Cherie Priest. Checked CD #10 and we were back to Paretsky's book. I've been on a waiting list for this book on tape for over a month. Hard to believe the previous listeners didn't notice #9 was a different novel. Haven't been able to come up w/ a plausible scenario of how this could happen. So I got a deal w/ this book - 2 mysteries instead of just 1.