My last theory

[lazyvix3n]

No: HPFGUIDX 137503

After my first read of HBP and joining this group, I was prepared to
concede that Snape might be good and that Dumbledore's death may have
been a part of some cunning plan. This has gnawed away at me for weeks
though, particularly as I read the book for a third time.

We're talking about Snape here. Snape who has been absolutely awful to
the likes of Ron, Harry and Neville throughout the books and who we
assume has been the same with countless other young kids in Potions
and laterly DADA lessons throughout that time. The scene in "Snape
Victorious" where Snape comes to the gate sums up Snape really well,
does he show any concern or sympathy for what might have happened to
Harry (face covered in blood)? Course not, he's Snape. But we expect
that with Harry, but the way he treated Tonks was outrageous.

I've seen some theories that were based on a dying Dumbledore having
his wishes carried out by a loyal Snape. Dumbledore himself indicates
that while the destruction of the Ring Horcrux seriously injured his
arm, that was all it did, at the same time saying that he wouldn't
sacrifice the other one for another Horcrux, perhaps a few fingers.
Does this sound like someone ready to die for the cause? The potion
could be killing him, but there's no way that Snape or Dumbledore
could have been certain of that even if they were able to have a
fleeting discussion via Legilimency on top of the Astronomy tower.

Dumbledore showed that he was not exempt from making mistakes, by
choosing to ignore Harry's warnings he put everyone in the school in
danger, and what for? to 'save' Draco? To find a way out of a stupid
mistake made by his DADA teacher in making the unbreakable vow? After
the cursed necklace and poisoned Mead, Dumbledore had realised that
Draco was out to kill him, with it being only him in any danger he
could chose to ignore it and let it play out. But Draco ultimately
found a way to get Death Eaters into Hogwarts, putting all of the
order members and the Students at risk.

My theory about Snape is this, he made the unbreakable vow for one or
all of several reasons, 1) Narcissa's manipulation was well done and
probably even more effective if Snape felt an attraction to her 2)
Wanting to look important in front of Narcissa and Bellatrix and 3)
Being curious about the plan and having lied about being in on it. Oh
yes, I feel convinced that Snape knew nothing of the plan before it
was mentioned and while he may have tried legilimency he would
probably not have had much success with 2 witches that were so
entrenched in the organisation of Voldermort. When he made the vow, he
was content with the first two parts, but got nervous when Narcissa
said the third but by that time there really was no going back.

Throughout the year, Snape tried everything he could to find out what
the plan was with no success, after all his life depended on it. He
may have reached the same conclusion as Dumbledore - that Malfoy was
going to try to kill our bespectacled headmaster - but we can't be sure.

On the fateful day, when Flitwick ran into Snape's office - presumably
proclaiming the presence of the dark Mark above the Astronomy Tower or
else why would Snape head straight there? - Snape stunned Flitwick to
prevent him from getting in the way and went straight to where the
action was, where he fully expected Malfoy to be and there he finds
Malfoy pointing his wand at a disarmed and unhealthy looking
Dumbledore. It takes seconds for the full understanding of what he'd
got himself into to sink in and for him to realise that there was
really only one thing he could do to save himself and save Draco. Well
you know the rest.

I guess this is just another version of the Snape being Snape theories.