"How’s it going over here?" Surely my two brightest students must be—" Slughorn seemed to materialize beside their table, bouncing on the balls of his feet as he looked down at the cauldron. Draco’s jaw snapped shut, his biting remark cut short. Slughorn’s smile disappeared slightly as Draco released her hand. He peered into their cauldron, his nose wrinkling.  "Coming along acceptably well, I suppose? You two are a bit behind today. I’m rather surprised."