Whether it had been built that way, or because he had used magical trickery to make it so, Slughorn's office was much larger than the usual teacher's study. The ceiling and walls had been draped with emerald, crimson and gold hangings, so that it looked as though they were all inside a vast tent. The room was crowded and stuffy and bathed in the red light cast by an ornate golden lamp dangling from the center of the ceiling in which real fairies were fluttering, each a brilliant speck of light. Loud singing accompanied by what sounded like mandolins issued from a distant corner; a haze of pipe smoke hung over several elderly warlocks deep in conversation, and a number of house-elves were negotiating their way squeakily through the forest of knees, obscured by the heavy silver platters of food they were bearing, so that they looked like little roving tables.