"Damn it! I knew we should have taught you those detection charms, especially since that's the same way you got Snape in your first year! I can't change the past, but from now on; I want you to be on your guard when anybody outside our family gives you something to eat or drink! I'll teach you the charms you need to know, and I never want to hear of you falling victim to something that simplistic again. Do you understand? Good! Now, tell me what you are planning." It wasn't a request.