—————After dinner Harry lined Ron and Hermione in the common room with her notes and the package. Out fell a small, square mirror. It looked old; it was certainly dirty. Harry held it up to his face and saw his own reflection looking back at him. He turned the mirror over. There on the reverse side was a scribbled note from Sirius.This is a two-way mirror, I’ve got the other one of the pair. If you need to speak to me, just say my name into it; you’ll appear in my mirror and I’ll be able to talk in yours. James and I used to use them when we were in separate detentions.