She paused, her chest rising and falling rapidly, the color high in her cheeks. Behind her, Narcissa sat motionless, her face still hidden in her hands.
Snape smiled.
“Before I answer you—oh yes, Bellatrix, I am going to answer! You can carry my words back to the others who whisper behind my back, and carry false tales of my treachery to the Dark Lord! Before I answer you, I say, let me ask a question in turn. Do you really think that the Dark Lord has not asked me each and every one of those questions? And do you really think that, had I not been able to give satisfactory answers, I would be sitting here talking to you?”
She hesitated.
“I know he believes you, but…”
“You think he is mistaken? Or that I have somehow hoodwinked him? Fooled the Dark Lord, the greatest wizard, the most accomplished Legilimens the world has ever seen?”
Bellatrix said nothing, but looked, for the first time, a little discomfited. Snape did not press the point. He picked up his drink again, sipped it, and continued, “You ask where I was when the Dark Lord fell. I was where he had ordered me to be, at Hogwarts School of Witchcraft and Wizardry, because he wished me to spy upon Albus Dumbledore. You know, I presume, that it was on the Dark Lord’s orders that I took up the post?”