Some food for thought, at least. I do think that it’s unlikely Lucius just happened to have the diary on him, and just happened to decide to give it to Ginny. He had a plan for that diary that day, the question is just whether giving it to Ginny specifically *was* that plan.

And about the vanishing cabinet, I always assumed it teleported one from one cabinet to the next, not actually forming a literal passage. But I agree with you, John, I think the cabinet would have to be closed all the way for it to send Harry, either between the two, or into Limbo, depending on whether the cabinet in B&B was broken or not. It’s also plausible that there would need to be some kind of magic used to activate them, however I doubt when Montague was shoved in, that whoever did the shoving (I think Fred & George?) would know of these words. Although (and I hate to use the movies as a point of reference, but) in the movie for HBP, Malfoy uses the term “Harmonia Nocterne Passus” to activate the cabinets. Though, this is the movie, so it can’t exactly be called accurate to the universe 100%.

Arthur and Narcissa are second cousins once removed. That’s a sufficiently distant relationship should they wish to avoid one another, but they probably did have some acquaintance in common and move in the same circles occasionally.

BestSeriesEver, it seems to me that the Trace detects all magic performed in the vicinity. The Ministry doesn’t worry about it if an adult wizard lives in the household, but if a school-aged child is the only wizard inhabitant, or if it happens in a public Muggle area, that’s when the law is considered to have been broken.

But Fred & George? It’s possible you can do a certain amount of potions without strictly doing “magic”, in the same way you can use a magical gadget without casting a spell yourself. I think Molly just hoped that was the sort of thing they were doing and didn’t ask too many questions.

Correct me if I’m wrong, but from what I remember, the trace does detect underage magic, it’s just that there is so much magic that goes on in a wizarding household, from cleaning to repairs to accidental magic that the kids may do, that they really can’t distinguish who is responsible for what in that setting.

Also, I was under the impression that the ministry only punished kids when the magic was performed intentionally and/or in the presence of muggles, thereby violation the Wizard Privacy Act(?).

So, if I am correct, the only reason Harry was punished was because it was in front of Muggles AND intentional.

However, this doesn’t explain why Harry was blamed when, in fact, it was Dobby, who wasn’t even supposed to be there. The only real explanation that I can think of is that either, A) The trace simply detects magic, weather or not it was intentional, and which wizards were there, so, Harry, being the only wizard, was blamed, or B) Dobby did some form of deep, house-elf magic (like we will see him do later on in the series), that tricked the trace.

The second option is the one that I personally subscribe to, just because Dobby was trying to keep out of serious trouble and get Harry expelled at the same time.