"I’m glad to hear it," said Snape, with the tone of someone who wasn’t very glad at all; he turned his penetrating gaze on Draco, "Mister Malfoy, it appears that Mister Crabbe never returned to the dormitory last night. I wondered if you perhaps had some idea why that might have been?" Draco was certain that Snape already knew the answer to his question, but he clearly had no evidence, or he wouldn’t have been asking him in the middle of the grounds.