"Yes, yes, admirable spirit."
Snape said in a dry voice,
"Of course, sitting in prison was of little use to him, but it was undoubtedly a fine gesture—"
"A gesture!"
She shrieked. In her fury, she looked slightly mad.
"While I endured the Dementors' torture, you hid away at Hogwarts, comfortably playing Dumbledore's favorite!"
"Not entirely," Snape said calmly. "He refused to give me the Defense Against the Dark Arts post, you know.
He seemed to think it would cause me to fall again... tempt me back onto my old path."
"So that was your sacrifice for the Dark Lord? Not being allowed to teach your favorite subject?"
She sneered. "Why did you remain there, Snape? Still secretly spying on Dumbledore, for a master you believed dead?"
"Perhaps not,"
Snape said. "But the Dark Lord was pleased that I had not abandoned my post: when he returned, I could offer him sixteen years' worth of intelligence on Dumbledore, a far more valuable gift than endlessly recounting the miserable conditions of Azkaban..."
"But you stayed—"
"Yes, Bellatrix, I stayed."
For the first time, Snape showed impatience.
"I had a comfortable job. Why should I have gone to Azkaban to be imprisoned?
You know, they were rounding up Death Eaters then.
Dumbledore's protection spared me prison, and I saw no reason not to take advantage of such favorable conditions.
I will repeat myself: The Dark Lord did not complain that I stayed behind, so I do not understand what gives you the right to criticize me.
I suppose the next thing you wish to know is,"
he pressed on, raising his voice slightly as Bellatrix clearly made to interrupt him, "why I prevented the Dark Lord from obtaining the Philosopher's Stone. That is an easy question to answer.
He did not know