Severus Snape was first and foremost a teacher. After the war was over, that's all he was. The sudden withdrawal of the huge responsibility he had been given in the lead up to the war meant that not only was he bored, but he was also lonely. He had resigned from his post as head teacher. Even though the children now knew his part in the downfall of Voldemort all too well, they still found it difficult to trust him, especially the Golden Trio, who hadn't so much as looked at him since they had returned to Hogwarts to complete their final year, except Harry, who was obliged to mutter his thanks in passing.
You couldn't so much say that the war had changed Severus, more that the termination meant that he could now be himself. He, like the majority of the wizarding world, had lost too much, and even the guarantee of increased safety could not change that.
He found himself going through the motions, eating, teaching, marking, reading, sleeping, and then waking up the next morning and repeating his routine again and again for weeks and months, but never putting any soul into it.
He was reflecting on this while his seventh years completed their liquid luck potions. Felix Felicitus was a very tricky potion to master, which explains why he was astonished as Hermione Granger approached him, having finished the potion quicker than he had anticipated.
"Sir, I think I am finished."
His dark, hooded eyes slowly looked up from his scratched wooden desk. Her hair was tangled, her face was covered in a thin layer of sweat and her clothes were a mess, half of her shirt had come loose from its original position, tucked firmly into her skirt, and her breath was slightly ragged. The potion had been a hard one but she was almost positive that she had got it absolutely correct, the only nagging fear she had was that Professor Slughorn had stated, when introducing it to the class only two years ago, that it was "disastrous to get wrong". It had taken six months to brew, and many of her classmates had missed out a step, or made a slight error, resulting in the necessity to start again, but Hermione, being methodical and bordering on obsessive compulsive, had not made a single error along the way. Now, however, at the last minute, she was terrified of the prospect of it being wrong.
He had said this in a voice that would have previously terrified the child, but with the war had gone his terrifying authority. He tried to catch Hermione's eye as she nodded, but she refused.
"Give it here."
He held out his hand and she passed him the potion, careful not to spill a drop. Once it was in his hand, he immediately brought it to his lips.
"No, professor, don't, what if it's not right..."
She looked flustered and he allowed a slight smile before taking a sip of the potion, ten hours luck worth. Nothing happened for a moment, and the whole class went silent, turning to look at their professor, who had taken a huge and unnecessary risk for no apparent reason.
Then, after a few seconds, he noticed the effects of Felix Felicitus, he felt as if he could do anything, but at the moment felt a huge pull towards Headmistress McGonagall's office.
He was slightly disappointed that the potion hadn't been wrong, surely that would have been easier, to die on the spot, to quit this dreadful excuse for a life, but of course he could not expect Hermione of all people to make a mistake.
He heard her sigh of relief as she realised her potion had been successful, then the cheering as the class, a few minutes slower than her, realised also, but he didn't care about that.
"The insufferable know it all gets it right again, congratulations Miss Granger, ten points to Gryffindor."
The last part had to be forced out of his mouth, old habits die hard.
"Pack away, the bell will be going in a few minutes, and try not to break anything."
He said in a condescending tone before rising out of his chair and sweeping from the room, his cloak billowing behind him.
Snape knew before he entered Minerva's office that she wouldn't be there, she was teaching still as no replacement for her had been found, but he still had an overwhelming urge to go there regardless.
He entered like he always had, with a mask of confidence and an air of authority, but then when it was confirmed that the room was empty, he let his shoulders hunch and his face relax, the relief was almost unbearable. He let a slight smile play on his lips at the realisation that he had been pretending for too long.
"You should smile more often, Severus, it suits you."
He jumped as the old headmaster spoke. Dumbledore was rarely available there as he preferred to travel between paintings so Severus had given up trying. Snape had been affected much more by Dumbledore's death than he let on, it had almost made him give up his job, both as a teacher and a spy, but Dumbledore wouldn't have wanted that, he had told him himself.
"Albus, do you want to give me a heart attack?"
Dumbledore didn't answer, just laughed slightly.
"Someone's had some liquid luck."
"I was simply testing a student's capability in Potion making."
"How did they do?"
Severus sighed, but this conversation felt right, so he simply answered the question.
Dumbledore smiled with a twinkle in his eye, Snape knew that smile, he was up to something.
"Hermione Granger, I presume?"
Snape's eyes widened as he looked at the man who always seemed to know everything.
"How did you know?"
Albus once again ignored the question.
"Watch out for Hermione, she's... important."
Before Severus could ask one of the many questions in his mind, Albus was gone.
"Come back here, you coward!"
Snape growled at the painting, but it did no use. Maybe the potion wasn't working after all.
Hermione had walked out of the classroom, perplexed about Professor Snape's sudden departure.
"Where do you think he's going?"
She asked Harry and Ron as they appeared either side of her.
"Don't know, don't care, that old git was probably going to..."
Hermione interrupted him, she didn't want to hear what bizarre and untrue stories Ron had come up with to explain Professor Snape leaving the classroom a few minutes early.
"Leave him alone, Ronald, without him we'd probably all be dead."
"Calm it, 'Mione, I was only joking."
He draped his arm around her shoulder and she shook it off, he still hadn't got used to the fact that they weren't going out any more, she had told him their relationship wasn't going to work shortly after the downfall of Voldemort. She had said this was due to the fact that she had changed with the release of pressure, but really he was too self obsessed and dim-witted for someone like her to ever love. Ron persisted, trying for her hand this time, but she shoved him slightly with her shoulder, held her books closer to her chest, and turned the corner towards her next lesson, smashing directly into Professor Snape's chest.
"I'm so sorry, sir, I wasn't looking where I was going."
Instead of saying something sarcastic or rude, as she had expected, he grabbed her arm and dragged her in to the nearest classroom, which was luckily empty.
"Miss Granger, do you know what you are planning to do when you finish this year of Hogwarts?"
She had thought about it, maybe too much, but he wasn't exactly the person she wanted to talk to about this.
"No, sir, not much anyway."
"Even though I know that cannot be true, I will let this one slide. Miss Granger, have you ever thought about going in to teaching? Before you answer, can I just inform you as to why I am asking. You see, the Headmistress has given me permission to teach Defence Against the Dark Arts as long as I find a replacement for myself, and your display in today's lesson just reinforced my view that you would be an excellent choice."
Also, it would be so much easier to find out what Dumbledore had meant about watching out for her if he obeyed. Hermione looked flustered, before exclaiming that she would have to think about it and escaping.