Erwin was momentarily stunned, a look of bewilderment flashing in his eyes.
Snape said coldly, "Did you really think that after he drank my potion and I left my own secret safeguards on him, I wouldn't notice a thing?"
Erwin shook his head. "No, Godfather, you misunderstood! I never doubted that for a second. The moment I gave Professor Quirrell that potion, I figured you would find out. What I'm surprised by is that you didn't know Professor Quirrell's actual situation?"
Chapter 174