so i came up with two theories about the harry potter book which i wish were true but i highly doubt that they were except maybe the second one
The first one is I think that Dumbledore asked Snape to kill him if anything bad should happen. On page 405, the chapter called Elf Tails, Hagrid tells Harry that he overheard Snape and Dumbledore talking.
"I dunno, Harry, it sounded like Snape was feelin' a big overworked, that's all - anyway, Dumbledore told him flat out he'd agreed ter do it an' that was all there was to it. Pretty firm with him. An' then he said summat abou' Snape makin' investigations in his House, in Slytherin. Well, there's nothin' strange abou' that!"
That sounds a lot like Snape agreed to kill Dumbledore. Page 595, chapter called The Lightning-Struck Tower:
"Severus...please..." Dumbledore was pleading with Snape to kill him. Begging him to kill him. I'm thinking that Dumbledore made Snape promise to kill him, just like he made Harry promise him all of those things in the cave.
And even though it said Snape had hate in his eyes....well do you have to be hating something to do the killing curse??? i mean he could have not even been thinking about Dumbledore even though i dont think Dumbledore's excuse to trust Snape was good enough I can still hope that this can turn out good.
Ok second theory...I think Dumbledore made Snape Defense Against the Dark Arts teacher since Harry didn't get an O on his OWL That way he could take potions and become an Auror because all Dumbledore pretty much always wanted to do was make Harry happy and that would make him happy.
ok im done now let me know what you think.