The corridors were empty. I was the only one walking. The next class was biology and I made my way sauntering past the glass windows on my left and lockers on my right. I was about to take stairs for the class when something on the window caught my eye. On one of the windows, a condensed patch appeared. It was odd because the rest of the area on the glass window was clear. It seemed as if someone has blew hot breath on it. The patch got thicker and denser.