Igor Karkaroff was coming to the school. Severus had not seen him since... well, since they were boys. They had been boys, no matter what they had thought at the time. Oh, he had watched Dumbledore's memory of that terrible hearing in their Pensieve. It wasn't that so much. Betrayal was hardly betrayal when it was extracted under torture. The biggest problem was that Severus' Dark Mark was returning to clarity, its glyph sharpening from greying indistinctness to definite, outlined black. The Dark Lord was returning, and they would all have to choose sides once again.
His road was a tightrope and he would need to step very carefully to avoid falling to one side or the other. Karkaroff was too unstable a factor in his extremity, and he would likely swing the rope to bring Severus crashing down.
Karkaroff had come to him, worried, almost panicking. Severus forgave him. His time in Azkaban had been longer and thus more scarring than Severus'. But of course he had no advice to give him, and they were interrupted.
The next time they met had been the ball. They had stood together by the wall near the punch bowl, watching the churning students. And was that... Yes. Professor Flitwick.
"I brought you something," Karkaroff said, in his deep foreign voice, "from Bulgaria."
This was not something Severus had expected, though he now remembered a similar package in Karkaroff's hand the first time he had approached. "Thank you." Severus scarcely knew what to say and was trepidatious.
It was a large jar of tallow, wrapped in brown paper. "Hirschtalg. From the reindeer of the north which are able to fly and disappear at will. I thought it might be of use in your potions."
This was something precious and very rare. Karkaroff's eyes had grown a new dignity with his position, but behind the surface they begged for forgiveness. Severus turned it over in his hands. "Thank you, Igor."
It was acknowledgement of the forgiveness Severus had not thought was necessary. But it would be 'Igor' now, not 'Karkaroff.' They went outside together to monitor the gardens, carriages and other small secret spaces, patrolling for amorous students.