Ich habe genug,
(I have enough;)
Albus has known, for months now, that he is dying. Plans upon plans have been reworked. He half expected not to come back to Hogwarts at all, to die in the sea-cave. It has been a pleasant bonus to be able to offer the hand of mercy to Draco Malfoy; a shame the boy will not be able to take it, that he remains enmired with no way out, but his having passed this last test will be good for his soul regardless. Mercy, and mercy, and mercy. There is inevitability in this. Severus will be here soon, to grant one more mercy. Albus is ready.
Ich habe den Heiland, das Hoffen der Frommen,
Auf meine begierigen Arme genommen,
(I have taken the saviour, the hope of the pious,
Into my eager arms;)
He does not regret using that last split second, as the door burst open, to immobilise and silence Harry. It was worth it. Harry is the future, the Child of Prophecy, the last hope, the saviour of the Wizarding World. The boy will die, yes, but not now. Not at the hands of Amycus and Alecto Carrow, Fenrir Greyback, Thorfinn Rowle. Grubby little nothings, all. No, the boy is meant for better things. He remembers holding the small, blanket-wrapped bundle in his arms, that night on Privet Drive, the tiny, chubby face relaxed in sleep, the messy hair, the scar. That terrible, fateful scar. He had not known then, no, but he had suspected. Laying the child down on the doorstep had felt like relinquishing something more profound, something he thought he had cast aside with Gellert. Once again, he was resolved to countenance great wrongs, for the greater good.
Ich hab ihn erblickt,
(I have beheld him;)
Albus remembers his first sight of Harry as a boy rather than a baby, such a normal-looking child in the crowd of first-years waiting to be Sorted, nudging and whispering with the Weasley boy, face full of interest and hope, not cold and aloof like Tom. The sorting into Gryffindor. The same face on hospital pillows, covered with the muck of the fabled Chamber of Secrets, pallid by torchlight and its reflections in the golden Triwizard cup, earnest, trusting, angry enough, at the worst, to destroy a few pieces of bric-à-brac and furniture, but never twisted with true malice, never closed-off. Such a reassuring sight, always, this boy, growing and learning in line with Albus' plans, innocent and devoted.
The door bangs again, and Albus' other protegé is on the scene. He too has dark hair, but dark eyes to Harry's lucent green, formal robes to Harry's delightfully eclectic Muggle garments, sallow skin to Harry's fair, ugly features to Harry's handsome ones. Night and day, really. Gryffindor and Slytherin. And Albus has guided them both to this point; from here, they have a clear path to the end.
'Severus...' he croaks, throat burning from the potion, lungs gasping.
Mein Glaube hat Jesum ans Herze gedrückt;
(My faith has pressed Jesus to my heart;)
Severus pushes young Malfoy aside to stand directly facing Albus. They stand eye-to-eye for a moment, and breathe. Severus never explicitly agreed to do this, always cavilled, but Albus knows him. The disdain and disgust on his face is not only a mask; it will fuel the spell. Albus has faith that Severus will do his duty. Duty is all the man has known for sixteen years. And Albus has faith, too, that the Dark Lord will be defeated, even though Albus himself will not live to see it.
Nun wünsch ich noch heute mit Freuden
Von hinnen zu scheiden:
(Now I wish, with joy, this very day
To depart from here:)
"Severus, please," he says, the enthroned ruler of Hogwarts turned humble penitent, even at the tallest height of his beloved castle-kingdom. The onlookers, visible and invisible, must believe he is pleading for mercy, and so he is. Battlefield mercy is still a kind of mercy. There is more fear in his voice than he knew. He does not fear death, but for a moment he fears Severus may show a different kind of mercy. He is a formidable wizard. He knows - and has invented - powerful spells to heal, as well as to harm, a dual-natured man long before he became a double agent. He has survived far worse odds than five-on-one, four when one considers that Draco Malfoy - so weak, so soft, so vulnerable - would hardly turn his wand on his beloved godfather. Severus is capable. But people do not do everything they are technically capable of. Habit and temperament rule, and Albus has guided and encouraged, nudged and ordered, closed down options, steered and suggested. Severus is many things, but Albus must trust that in the end, he is what Albus has made of him. Severus desires the defeat of Voldemort above all else. He will do his duty. He must.
Severus raises his wand.
"Avada-" Triumph fills Albus' heart.
Ich habe genug.
(I have enough.)
"-kedavra."
Green light fills Albus' vision, and he is gone.