narcissa! cissy! you mustn't do this. he can't be trusted. the dark lord is mistaken. or so i believe. he lives in this muggle dunghill? you must be joking. the dark lord told you? you? you should feel honored, cissy. as should draco -- swear to it. make the unbreakable vow. you see. it's just empty words. oh he'll try. he'll give it his best effort. but when it matters most he'll slither back into his hole. bloody coward. will you, severus snape, watch over draco malfoy as he attempts to fulfill the dark lord's wishes. and will you, to the best of your ability, protect him from harm? and should it prove necessary, if it seems draco will fail. will you yourself carry out the deed that the dark lord has ordered draco to perform? well now, look what we have here. dumbledore. wandless and alone. cornered in his own castle. well done, draco. love to, albus. but i'm afraid we're on a bit of a tight schedule. do it. malfoy's wand rises once again. harry raises his own, aiming through the grid, poised. just then, a shadow splinters through the columns to his right. he looks, finds snape, quiet as a ghost, peering upward. carefully, snape draws his wand, then turns to harry, a finger to his lips: shhh. then he is drifting upward. silent. a ghost again. no! the dark lord was clear. the boy's to do it. go on, draco. now! once again draco raises his wand, his hand trembling. harry's own arm is stiff, sure. the vein in his hand pulsates. well, look who's here. hogwarts own defense against the dark arts teacher. come to see the slaughter? boo. draco! draco! they'll kill you if you stay.