You don’t want to make a scene but really don’t want to speak to that person. It might be that they speak too long and you’ll waste your entire day, that you’re chemistries just don’t mix, or that their is some underlying anger you’ve left behind from your last conversation, so how can you escape? There could be the walk the other way, look down, drop something under you desk, or the old itch all over your face that might come to your rescue. Yet sometimes those tricks just won’t work because their lingering over your area just a fly that can’t be swatted away. For those times the offensive must be taken. Make sure you say a big hello as if it was a goodbye and then before they even have a chance to respond make sure that you and they notice that you just don’t have a moment to continue this conversation then leave until the next time …. in hell.