Slytherin common room

This is the scene in the second book when after the Christmas feast Harry and Ron trick Crabbe and Goyle into eating enchanted cakes. It shows when Harry and Ron are in the common room and are talking with Malfoy. In the common room is a Slytherin banner, and a a glass tube connected to the wall. It includes Malfoy, Harry and Ron disguised as Crabbe and Goyle, a letter and a small candle. Good luck!