Professor Severus Snape's eyes darted around the school grounds that were empty apart from the lone figure that he had been searching for. Ah, there he is... Skulking over, he stood a few metres behind his mentor, his friend, the person who had accepted him and taken him in, saved him from Azkaban and trusted him. Trusted him too much, so much that he had trusted Severus with the one act that could save the wizarding world, and many lives. And lose the most important life of all.
"Headmaster, I've been meaning to speak to you..."
Albus turned around to face Severus and there was a glint in the old man's eye as if he had expected Snape to come looking for him at some point. "Ah, Severus, I thought you would come to find me sometime."
Snape's face remained emotionless, until he spoke. "I refuse to do it," he said angrily, straight to the point, and Dumbledore understood completely what it meant.
"I'm afraid Severus, you have no choice. You made the Unbreakable Vow to Narcissa, and now you must carry out your promise. Its as simple as that," Dumbledore said cheerfully, taking a sherbet lemon out of his clock pocket, unwrapping it and eating it.
A look of disgust on his face at the thought of what he would have to do, Severus replied angrily, "How can you expect me to do that? I could not bring myself to... anything else you could ask of me, I would do; I have been your spy, I have carried out all your orders, have I not? Anything, but this..."
"You have agreed to do it, and that is that," said Dumbledore, in a practical way, as if he were instructing a child to tidy their bedroom. "You know what happens if you break an unbreakable vow, I am sure?"
"Of course I know," Snape snapped at Dumbledore. What would the wizarding world do without the only wizard You-Know-Who was ever afraid of? Of course Hogwarts would have to close, and Severus would rather die himself than kill the only man that had ever trusted him.
"To the well-organised mind, death is but the next great adventure," Dumbledore said with a smile. "One of my more brilliant lines."
Seething with frustration at the man that stood before him, Snape took one last look at Dumbledore before storming off towards the castle, knowing that in the end, he would have no choice but to do what Dumbledore had instructed, and he would forever hate himself for carrying out Dumbledore's final order.