During the scene in which Malfoy has cornered Dumbledore, Malfoy is bragging about how Dumbledore did not know it was him who was behind the cursed necklace and the poisoned mead:
“As a matter of fact, I did,” said Dumbledore. “I was sure it was you.”
“Why didn’t you stop me, then?” Malfoy demanded.
“I tried, Draco. Professor Snape has been keeping watch over you on my orders-”
“He hasn’t been doing your orders, he promised my mother -”
“Of course, that is what he would tell you, Draco, but-”
Now, if you Snape and you were working for the Order, wouldn’t he have told Dumbledore about the Unbreakable Vow? Because it certainly doesn’t seem like Dumbledore didn’t know about it. I have always believed that Snape was in the Order, and was ordered by Dumbledore to follow through with the Unbreakable Vow. After reading this book again, I think that Snape was a Death Eater
I know, I am sounding like a flip flopper, but I just can’t figure it out! It’s driving me crazy! Thoughts anyone?