Severus Snape sat at the desk in his office grading third-year essays. He idly noted how Longbottom's understanding of plants really shone through in his writing. The boy had really started to do well in his class once he had begun making a conscious effort not to intimidate the child. Many of his students had, in fact. He wondered again at how self-absorbed and blind he had been to how his behavior affected those he instructed. Before Harry, he had never really thought about it.

As he marked the paper with a large red 'E', there was a knock at his door. "Come," the Potions Master called. He would have never expected the person who then stepped through his door, shoulders drawn and head bent like an errant schoolchild.

"Black," Snape greeted neutrally, proceeding to grade the next essay. "I do believe that Harry is meeting you at Remus's office, rather than here." He was not consciously aware of the fact that he'd referred to the Defense instructor by his given name, though the animagus hadn't failed to notice.

They really are getting along, Sirius reflected a bit grimly. He responded aloud, "I know. I, uh... I came to see you. I have something I need to say."

The Professor's quill paused over the parchment before he carefully set it aside. Raising his head, he arched a brow at the other man. "Oh?" he queried silkily. "And whatever might that be?" It was a struggle to remind himself that for Harry's sake he wanted to at least be civil to the man.

Squaring his shoulders, Sirius gave a nod, more to steel himself than anything else. "I..." he swallowed, finding that what he wanted to say was more difficult than he'd anticipated. This was something he wished to do, however. It was like he'd told Draco, about the difference between a good and a bad person. Sirius Black was done making excuses for his own misdeeds.

"I'm sorry," he blurted out. "I'm sorry that I lured you to the Shrieking Shack back in fifth year when Remus was in his lycan form. You could have been bitten or killed and... it wasn't right. Even if I don't like you, it wasn't right to do that to you. I'm sorry, Snape. Truly." A young boys words rang in his mind as he spoke, resonating with him – I don't want to be that sort of person, I don't!

"Your apology is a little late," Snape drawled impassively, peering at the man across the room.

"I know. To be honest, I should've been sorry a long time ago, but I wasn't," Black replied frankly. "But now, I am."

The Potions Master gave a very slow nod. "I suppose that I have committed my share of wrongs against you, as well," he said.

Sirius nodded back, knowing that that would be the end of it. He turned towards the door and Snape reached for his quill, before he paused again.

"One more thing, Snape," the animagus declared, meeting the Potions Master's gaze. "If you ever do wrong by Harry, if you ever hurt him, I don't care whose son he is, you will be very sorry."

Severus held the man's gaze steadily, faint amusement entering his expression. "If you were not willing to defend Harry in such a way, you would not be worthy of being his godfather," he replied.

Sirius hesitated, a newfound respect for his old nemesis sparking within him despite himself. "Good," he said, opening the door.

"Good," Severus echoed, returning to his work.

Somehow, they both knew it would be.