There's nothing like getting to the bottom of a mystery, especially when you break a man under interrogation and he gives himself up . . . Friday, I noticed that there was a black mark on my pull down projector screen, and this made me angry because I use this screen all the time-- I write things on the white board, and then I pull the screen down and project video or a quiz or an image, and the advantage of having the screen, is that I don't have to erase the stuff that's on the white board; it's very convenient . . . but now this big black mark was going to be omnipresent in everything I projected . . . totally annoying . . . and so when this new guy came into my room period nine (he teaches a class in my room while I have lunch) and pulled down the screen, I said to him "I don't know what happened, but there's a black mark on the projector screen" and he said "I'm sorry, that was my bad, all the other rooms have Smart Boards and I mistakenly thought I was writing on a Smart Board" which was, ironically, very dumb, because you write on Smart Boards with these fake computerized markers, but whatever, I was just glad I had solved the mystery, and once I broke him and got him to confess, I lightened up and said, "at least it wasn't malicious, I thought it might have been a student that did it" and then I painted over the black mark with White Out, pleased that I could put one into the "solved" file.