Disclaimer: The characters here and the world they inhabit are the creation and property of JK Rowling and her assigns.
Severus found himself enjoying the summer break more than he had in a very long time. During the day, the professors in residence went over their curricula and straightened their classrooms. They submitted requests for materials and assessed the likely abilities of returning students even as they pondered the students who would be new to their classrooms in the coming year. Septima would have a head start with that since no one entered her classes as a first year and she could ask other professors.
This summer she chose to ask Severus. They spent their evenings in one or the other of their studies, going over class lists. After Septima knew everything she could about the two years' worth of students she would meet this term, they moved on to various periodicals they received. They enjoyed reading other people's work together and then picking it apart, searching for the flaws in another wizard's research or deciding to congratulate a witch on her astute work. Those evenings always ended at the staircase, with Severus heading toward his rooms in the dungeons and Septima climbing up to the faculty rooms near Ravenclaw tower.
Severus often wondered, as the conversations occasionally shifted to their own work, what would happen if they discovered something brilliant. There were times already when he looked at Septima and too quickly imagined pulling her into his arms. He was sure that the elation of intellectual triumph would be too much to resist.
Already he was becoming aware of her as he had been back in their university days. He watched her explain a tricky equation and realized that the glow he had originally found attractive had returned. At night he pictured her in the bed beside him. Then he imagined her face as she told him she was pregnant and the look of betrayal that would follow when she was barred from the school. He couldn't allow it to happen. This glow, this joy in her work, must be preserved even if it killed them both. From the reproachful looks she gave him as he bade her goodbye without a touch, he knew it was as difficult for her as it was for him.
As the school year began, they spent less time together. He decided it was for the best even as he found grading essays and tests to be cold and empty work. He had such hopes during the first hour or two of the Welcoming Feast that his obligation to James Potter's whelp would be at an end, but the boy finally showed up, and the Headmaster denied that the boy had done anything worth expulsion. A great many hopes had surfaced and were forced back down for an indeterminate future.
A strange sign was painted in the school, and rumors began. A mythical Heir of Slytherin supposedly opened an equally mythical Chamber of Secrets. The situation got more serious when Filch's cat, Mrs. Norris, was turned to stone. Severus was brought to consider how to return Mrs. Norris to her proper state. After discussion with Poppy, it was decided that the best restorative would be a potion made with Mandrake. A new crop of the plants was currently growing, and Severus could easily make the potion when the plants were harvested.
One night he found Septima standing before her favorite window. Her hair had grown down to her shoulders since she arrived back. Usually she wore it in a bushy pony tail reminiscent of their early days together, but right now it was loose and gleaming. He snuck up behind her and whispered, “What would you do now if I was the monster from the Chamber of Secrets?”
In response she leaned back into his body and reached behind her head to circle his neck with her arms. “Oh, Heir of Slytherin, if I promise to do everything you desire, will you be gentle with me?”
He was assaulted by a great many desires and inclinations at once. At the forefront, his desire to put his arms around her and explore the soft flesh close at hand warred with his inclination to drop her and run to the dungeons. Why must pleasure and disaster be married in his life?
“Why are you doing this?” he whispered into her ear as he nibbled the lobe. “Why are you even here?”
“I've been thinking.”
“I could safely theorize that part.” He moved down to her neck as his hands worked the fastenings of her robe.
“Severus, what if I made the potion?”
He stopped and took a step back, his hands grasping hers and gently removing them. She turned around and stepped toward him. He stepped backwards again.
“If I make it, then none of your hair or skin can get into it by mistake, and we won't have that problem. You could supervise me.”
“But if the slightest thing goes wrong...” He stopped speaking and turned away from her. Then he realized... “You wouldn't mind, would you? You would allow yourself to be banished from the life you know over this.” He took several steps away from her and then turned around again.
“I—You know how I feel about you.”
“That's the problem, Septima. You would give yourself to me, body and soul, and while there are many things about you that I love, I—I can't do that. I can't promise myself that way.”
She started blinking fast. “It's still the other witch, isn't it? It always has been. You've always shared your body freely with me, but she's got your soul fast.”
“I can't deny it. She's gone far beyond my grasp, but I still—I can't give you what you should have from the man you love. I'm sorry. I wish you could try to forget me.”
She nodded and said, “I understand,” but he could tell that she was just being brave for his sake.
A/N: Thank you to Trickie Woo for beta reading!