Lessons have finished for the day and I have about two hours to spare until I have to meet with my tutor. I can think of a perfect way to spend them.   I reach the entrance to the dorm block and run up the flight of stairs. The door is right at the end of the long corridor. I tap softly on the wood and hear a deep voice call 'It's open.' Pushing the door open, I step in and then close it gently behind me.