How did Black get into Hogwarts in PoA? (Was: Dumbledore on the Dursleys . .

[pippin_999]

No: HPFGUIDX 151783

Carol:
> 
> As for the front doors, I suppose that the ghosts could have watched
> them in shifts, and Crookshanks could have reported that information
> to Black. I don't suppose that Harry would have noticed their
> presence. That being the case, Black would have had to use one of the
> secret passages (other than the one from the Shrieking Shack, which
> doesn't link to the school). But the four that Filch knew about would
> also have been watched, if only by portraits or ghosts, right? And
> surely they would have reported the emergence of a dog from one of
> them as an unusual and suspicious event, especially if that dog headed
> toward Gryffindor tower. (I still don't see how a dog could have
> sneaked into Honeydukes to use the hump-backed witch passageway, and
> the remaining passage was already blocked when Harry received the map
> from the Twins.) I suppose it's possible that neither Filch nor
> Dumbledore suspected that Black knew about the secret passages and
> consequently saw no need to watch them, but after the first incident,
> you'd think they'd have done some rethinking.

Pippin:
If Crookshanks was working with Black by Halloween, he could have
distracted the ghosts or portraits watching the passages or the
staff at Honeydukes. Or Sirius could have arranged a diversion --
lobbed in a dungbomb or something, that would seem like the
work of mischief-making students. I think, though, that everyone
assumed that Black didn't know about the passages because
Voldemort had never attacked the school, according to Hagrid
in PS/SS, and most people seem to have assumed he would never
dare to.

According to my theory, Black didn't need to use the passages
a second time. Lupin seems  emphatic that being an animagus
afforded Black some way to enter the school because otherwise
why would he have had to struggle with himself all year to 
convince himself that Black wasn't using it?
 
 I have to wonder about the Marauders during their time as
Order members,  keeping their knowledge  of the secret passages 
secret even after they knew one of their number had gone over to 
Voldemort. I suppose they were being protective of Lupin, and he, 
as always, was being protective of  himself. Anybody have a more 
Lupin-friendly theory?

Carol: 
> Elsewhere in the post you state, "we know that the killing curse
> can be performed without a wand." Can you tell me where you found the
> canon for that assertion and how it relates to Black (who evidently
> intended to use a knife)?

Pippin:
"Then kill him, fool, and be done!" screeched Voldemort
Quirrell raised his hand to perform a deadly curse, but Harry,
by instinct, reached up and grabbed Quirrell's face--
PS/SS ch  17

If you read the chapter carefully, you'll see that Quirrell doesn't
use a wand at all.

It doesn't relate to Sirius, but to the capabilities of Death Eaters -
Dumbledore would know that Sirius might be deadly whether he had
a wand or not. Even after they learned Sirius was using a knife,it didn't 
mean he wouldn't use a killing curse. 

As ancient magic is something Voldemort doesn't
appear to understand very well, I can see why Dumbledore would
rather trust it, both to guard the school and to protect Harry himself,
than sentient beings, who have proved to be so vulnerable
where Voldemort is concerned. I thought that the ancient magic
was put in place by the Founders, not by Dumbledore in OOP.

Pippin
not sure why theories that make Lupin look bad are less popular
than theories that make Sirius look bad -- sour grapes, possibly