Severus Snape: You sent for me, Headmistress?
Dolores Umbridge: Ah, yes. The time has come for answers, whether he wants to give them or not. Have you bought the Veritaserum?
Severus Snape: I'm afraid you have used up all my stores interrogating students, the last of it on Miss Chang. Unless you wish to poison Potter - and I assure you, I would have the greatest sympathy if you did - I cannot help you.