The deed was done. There were three things Severus had to do so that he could continue on his mission.
First, Number 12, Grimmauld Place, while he still could go back there.
The house was empty, soulless, in a state of advanced disrepair, cared for by no one. Knowing Harry was the owner of the house, and that he was bound to return there at some point, he cast every protective spell he could think of. His mental state was such that this wasn't saying much at all - there was his wretched inner life again, showing itself at the worst moment - performing the Killing Curse was very difficult magic and he was almost entirely depleted, unable to focus, distracted even by his own heartbeat.
He went into his enemy Sirius Black's bedroom with a feeling that could be described only as involuntary occlusion. His mind was closed even to himself. The world was not real anymore. In no plausible reality could he saunter into Sirius Black's bedroom out of his own free will or live to tell the tale.
He opened drawer after drawer, not knowing what he was searching for - clues to hide from the death eaters? Something that could tell him where Harry Potter might go next? Suddenly, he was struck by the face he last saw in Godric's Hollow, dead - Lily was beaming at him from a photograph, she was shining with happiness even as she was secluded away with James and baby Harry.
The rest of the world looked as if it was reflected back to Severus from a foggy, stained mirror, but Lily's face in the photo, her smile, her eyes, pierced his heart like an arrow. It started to beat wildly, thumping out of his chest.
He broke down and cried like a child.
There she was, forever young, forever the happy mother of a toddler, and there he was, holding her in the hands that aged 15 years, 15 years that felt like a lifetime.
The photo accompanied a letter. Oh, "Wormy" must have looked a little down alright!
The Ancient and Extinct House of Black had nothing more to offer him. He tore the photograph in half, and took the second page of the letter, containing Lily's love. "Will you let me leave James and Harry behind this time, Albus, or do I still disgust you?" he thought, as he left.
The second order of business - he had to take his seat beside the Dark Lord, in recognition of his remarkable achievement of killing a defenseless man who had less than a month to live anyway. The thought made his stomach lurch, but there was no ignoring the Mark's summons anymore.
He apparated to the Malfoy residence. Now above suspicion, he hoped his stride was that of a victorious person, as he tried to imitate James Potter leaving the Quidditch pitch. The world was again reflected to him from an unclean mirror, and for the second time that night, he opened the door to a room full of death eaters, only this time they were cheering for him.
The seat next to the Dark Lord was empty. He waved at the crowd with the appearance of modesty - or a true display of shame - and took his place as the Dark Lord's most faithful, his second in command, his favorite .
Lily's picture was in a pocket near his heart, and as they all continued to celebrate he could think only two things: "What am I thinking bringing this here?" and "oh Severus, the 16 year old you would have been ecstatic".
"Lord Voldemort rewards faithful service", his master said. "Ask, Severus, and you shall receive".
Severus shot a look at Bellatrix, who looked away, clearly ashamed - but he decided to be magnanimous toward the poor woman.
"First, I must acknowledge Draco Malfoy's contribution. Were it not for his faithful service and hard work, I might not have been able to accomplish what I did". Draco was astonished and Narcissa stared at him with silent gratitude.
"When I was his age, you may recall that I too could not perform the Killing Curse, but we can't all be the Dark Lord, and I firmly believe this day shows us there is no telling what might become of the younger members of this fine group."
He paused and looked around the room. Was this enough to make it so the Dark Lord could not kill Draco for no reason? It had to be.
"Second, I wish to start undoing the damage -" his voice broke… then he continued - "the damage Albus Dumbledore did to the august Hogwarts School of Witchcraft and Wizadry. I wish to be named Headmaster as soon as we take over the Ministry, and to continue to serve the Dark Lord from within the beloved castle."
Applause broke out. He raised a dignified hand.
"Lastly, though today is a happy day for all of us, we must remember Dumbledore was merely an obstacle we had to eliminate. Eliminating him was only a means to an end, and the end is Harry Potter. I had a chance today to kill him as well, and those who know me can probably guess I was quite tempted - but we must remember he belongs only to the Dark Lord. Let me waste no more of your precious time".
Applause broke out again, but they were muffled to him, as if coming from another room. He collapsed into his chair. When death eater after death eater asked him to regale the events of the night, he gladly referred them to Draco, hoping that retelling the story will help Draco remember what Dumbledore was willing to do for him, and that he was not a murderer yet.
He left his own party as soon as it was polite to do so.
There was one more thing he had to do - pay one last visit to Arabella Figg.