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

[justcarol67]

No: HPFGUIDX 151772

Pippin wrote:
> <snip> There are also four open passages into Hogsmeade that Harry
has never investigated because the Twins told him they are known to
Filch. Those might not need wands and they might be easier to get into
on the Hogsmeade side than the Honeyduke's passage. <snip>

> Sirius could have used one of the four passages to get into the
castle the first time. Maybe he didn't know that Filch had found
out about them, and he got lucky, or maybe he chose Halloween
because he knew that Filch and most everyone else would be
in the Great Hall. When he was thwarted at Gryffindor Tower,
he immediately left the castle through a hypothetical animagus portal,
remained on the grounds (probably *not* in the Shrieking Shack which
did not show signs of recent use) and entered the castle through the
animagus portal again when Crookshanks brought him the passwords. <snip>

> Pippin
> who always thought the extra secret passages were there just to have
a nice magical seven, and is happy to have found a use for them. And
who hopes Carol is feeling less lonely now
>
Carol responds:
Thanks, Pippin. I figured you'd agree with me about Lupin and the
Marauder's Map. I'm just astounded that everyone else seems to think
that Black just walked in and out the front doors on both occasions.

I don't think there's any mysterious "Animagus portal" and I do hope
for the story's sake (and Dumbledore's) that Black did use one of the
secret passages. Otherwise both they and the Marauder's Map seem
almost like red herrings. But JKR never does explain how he got in,
and Lupin implies that being an Animagus was all it took to do so, and
to me, still, that's just not a sufficient explanation.

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.

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)? DD would have known that Black was wandless
as his wand would have been taken from him before he went to Azkaban. 
(Speaking of wands, the DEs who escaped from Azkaban would also have
had their wands confiscated and those who are still at large must be
making do with stolen, borrowed, or second-hand wands.)

Carol, still wondering why no one else (other than Pippin!) considers
Black's method of entering Hogwarts in PoA an unsolved mystery worth
investigating