This is totally wierd

OK, this morning I woke up and found a clear DVD jewel case slid under my door containing Pirates of the Caribbean, Disc 2. I first saw it and thought, "That's nice, except I already have Pirates of the Caribbean." I looked in my DVD ox for it and lo and behold, it was not there. Apparently, someone borrowed the disc and then returned it. Unfortunately, I have no idea who borrowed it or could have borrowed it. Without a roommate I keep my door locked most of the time. If anyone knows who borrowed it, I'd like to know. I appreciate them returning it and if they want the jewel case back, let me know.