a) what if primary goal of this plot was never hurting Draco or Hermione, but to weaken Harry by making him relinquish his money/his claim to the debt from Lucius? Either the money or the claim to the debt that House Of Malfoy has towards him could be something that is dangerous to a hitherto unknown plan of H+C, which is why H+C devised a plot which would strip Harry of both. A genius (like Quirrelmort) could have predicted that Harry might offer either, in exchange for freeing Hermione. In fact, it might have... (read more)
I agree with bogdanb. "Hermione knows X by heart" is usually equivalent to "Hermione saw X in a book", and Hermione seeks out books.
4Alsadius
a) Unlikely, but I think it's a payoff that Voldemort will still consider to be worth the (rather trivial) costs of setting his plan into motion. It's not as ideal as denying Hermione to Harry, but it still imposed significant costs, which is all to the good.
b) Oh lord.
9bogdanb
Not really, she is indicated to be interested in history, and shown reading history books all the time. In another situation I would have be surprised by her willingness (given her wish to be “her own person”), but after being threatened with Dementors...
This has probably been mentioned before, but:
a) what if primary goal of this plot was never hurting Draco or Hermione, but to weaken Harry by making him relinquish his money/his claim to the debt from Lucius? Either the money or the claim to the debt that House Of Malfoy has towards him could be something that is dangerous to a hitherto unknown plan of H+C, which is why H+C devised a plot which would strip Harry of both. A genius (like Quirrelmort) could have predicted that Harry might offer either, in exchange for freeing Hermione. In fact, it might have... (read more)