He was so engulfed in his letter that Professor Roslund didn’t at first hear the gentle knock on his door. It was getting late, but that didn’t stop students from wanting to see him. Writing his signature at the end of the letter he folded the parchment up gently as he called out "Come on in. It’s open!" waiting to see who was there to grace his office with their presence next he plucked a liquorice wand into his mouth.