** We'd like to note that this is the first theory that has been written by someone other than Christina or Beth. **In the beginning of the novel, Slughorn introduces himself as the new Potions Master along with four potions. There's Veritaserum, Amortentia, Polyjuice Potion, and Felix Felicis. As their first lesson, they're instructed to make a batch of Draught of Living Death. This doesnt seem significant until the end of the novel when poof! I realized that all of these potions had a rather significant role in the book.
Ron mistakenly eats the chocolate tanted with the love potion which Romilda Vane intended for Harry; Harry mistakes Crabbe and Goyle numerous times for young girls doing Malfoy's bidding because of their abuse of Polyjuice Potion; and Felix Felicis of course has a significant part to play for Harry as well as his friends.
Veritaserum is mentioned quite a bit, but at this moment I can't recall when it was used--
Regardless, this leads to the last potion brewed that day. Draught of Living Death. This is the only potion that had been mentioned in that scene that had yet to play a part in the novel. It's my belief that Dumbledore is simply under the effects of the potion. If you aren't wholly convinced by this, take into account this little tidbit:
Every person who was killed by the Avada Kedavra curse in all six books died with their eyes open. I remembered for the sole reason that it creeped me out to no end-- but why would Dumbledore, under the same curse of death, have his eyes peacefully closed as he is found beneath the tower? And why would he summon for Snape of all people, so forcefully?
