When: The last prefect meeting before end of term
"...Which I really think someone ought to do something about, I mean, you can't just have people running about jinxing each other into Father Christmas hats that don't come off, don't you think, Andromeda?"
"Hmm? Oh, yes. Absolutely." She hadn't the vaguest idea what she'd just agreed to, but the Slytherin prefect who was talking seemed to accept her approval, and continued droning on. For her part, Andy hadn't been paying attention to the prefect's meeting for the last quarter of an hour. She was focusing on not glancing at Ted, which by association kept making her mind drift to the dream she'd had last night, which had started off very well and then gone horribly wrong. It was stupid, she told herself angrily, that a dream should make her feel this awful all day long. Ted had never come close to saying any of the things he had in the dream, terrible, hurtful things--but the trouble was, dream-Ted had been perfectly right about her behavior since the last Hogsmeade trip, and she knew it.
Still not paying attention as the topic of discussion changed to something else equally banal, Andy frowned at her meeting notes. From where the prefects were sitting, it would look as though she was keeping track of what was being discussed, taking minutes. Instead, there were a handful of bullet points from the first five minutes of the meeting followed by a sketch of a particular Roman fountain, which she was rather engrossed in embellishing.