The Case of the Missing Pens

Although I seem to buy pens incessantly, within a matter weeks after buying said pens, my desk drawer looks like this:


I have a couple Exact-o knives (one of which is missing a blade), a paper clip, a seam ripper, a safety pin, a silver pen that doesn't work, a red pen that doesn't work, a handful of pencils that need sharpening, a pair of tweezers...a log, a frog, a dog, a poodle, a noodle, a doodle... BUT NOT A BLUE OR BLACK pen in sight! Where, I ask, do all my stinking pens go? I think I'm going to have to call Nancy Drew to crack this case. Does anyone else have this problem?