A/N: This chapter is dedicated to new favoriter, MangoAiko. Welcome to the family!

-C

The seventh year students were difficult, not that Lydia was especially surprised. Ever since Valentine's Day, they'd been giggly, chatty, and gossipy. Not that this time of year was ever easy with students in their final year, but they were especially distracted. She wondered if this was what her group had been like, far more interested in their personal lives than in school.

Although, her group had a student found dead and a war on the outside, so personal lives were a bit more than just personal. But she tried not to let that inform how she interacted with students. It wasn't their fault that she had a difficult time of things at their age.

Still, she had to remind them that they had an exam coming up, so she cleared her throat. To their credit, they fell silent quickly, and they had the good grace to look embarrassed. The latest couple at Hogwarts were now sitting together, and Lydia noticed that he was spending more time looking at her than at his own work, where she was totally focused. It was a bit like Lily and James, if James had ever been self-conscious. Thankfully, he wasn't.

"I know life's interesting and exciting," she said, and the students smiled nervously. "I get that your exams are the last thing you want to think about. But it's my very unfortunate job to remind you that you do need to think of them, and of your careers, and of everything else you'd rather put off until later. Remember, many of you need this N.E.W.T. for your futures. And for those of you who don't, having a fail on your record still looks poor, even if it's an elective course."

A few students looked ashamed of themselves, so Lydia brightened the tone, asking students for updates on their projects. They were excited to tell her everything they'd found, pulling out their packets of research and notes and drafts. One girl had an analysis on the development of Quidditch through an Arithmantic lens, and Lydia's favorite thing about the project was that after she'd reviewed the historical aspect, the girl used the Rowe Theorem of Event Prediction to predict not only the next five world cups, but also developments in rules and league formation for the next twenty years. If it came out as well as it might, Lydia thought the girl had a book on her hands.

The students were eager to share everything they had, and as they were packing up in the last few minutes, Lydia asked how they felt about the upcoming Quidditch.

She hadn't expected the fervor of frustration that came her way in a wall, from both Gryffindor and Hufflepuff students. Mostly because she hadn't known what Severus had arranged.

"It really isn't fair," one Hufflepuff girl said. "I mean, does he even know anything about Quidditch?"

Lydia hesitated. She knew Severus must have decided to referee the match to keep a closer watch on Harry in case of another curse, but she couldn't very well say that to the students. She wasn't sure she was pleased with his decision, but she couldn't think of a better solution.

"He does, actually," Lydia said slowly. "He had…friends in school who played. I'm sure it won't be so bad—"

"Maybe for the Hufflepuffs," one Gryffindor boy said bitterly. "But he already takes every excuse to take off points for us. What do you think he's going to do if he has an opportunity to give points to someone other than us?"

"If you are suggesting he'd fix a match," Lydia said, more coolly than she'd ever spoken to a student, "I'd point out that he is your professor, and that's hugely disrespectful and insubordinate."

The boy's mouth clamped shut and he paled. Lydia felt a little bad for how quickly she'd admonished him. After all, if she'd had someone like Severus as a teacher, she'd probably have felt the same, especially if that teacher decided to referee her Quidditch match. But he was not her teacher. He was her oldest friend, and she understood better than any of them what his motivations were. Plus, she knew he knew that if Gryffindor lost because he was unfair, she wouldn't speak to him for at least a week.

"It's not, perhaps, ideal," she whispered. The whole class was silently waiting for her assessment, so they could hear every word. "But there isn't anything to change it now, so I suppose the teams will make the best of the situation, and the fans will have their opportunity to boo and hiss at Professor Snape, as I sincerely doubt they'll ever have a better opportunity."

There was a mild chuckle that rippled through the room, but she knew what they were thinking. The students knew she was friends with Severus, even if they didn't know the half of it. They expected her to defend him, although she'd always been fair and understanding when students had complaints about other professors—they just usually were about Severus—and she had validated those complaints where appropriate. This, though, she felt protective of. This was about Harry, and even if he didn't like Harry, he was going to protect him, even if he made a fool of himself in front of the whole school to do it. That was bigger of him than she could have ever hoped or imagined.

The students left in a quieter state than usual, but she went down to the staff lounge as quickly as her feet could carry her. Severus was just sitting down when she swept in, and he raised his eyebrows in subtle surprise.

"I want you to know," she said firmly, "that if you don't manage this match tomorrow with fairness and equitability, I will make your life miserable for some time."

Severus hesitated, but before he could think of a suitable response, she swept back out of the room. She didn't leave him to have an opportunity to talk her down.

The next morning, Lydia took her usual seat in the staff stand, feeling a little lonely without Severus in his usual spot. The stands looked more crowded than usual, perhaps because of Harry's last Quidditch incident, perhaps because students wanted the novelty of seeing Severus on a broomstick. Before she could decide what to do with herself, she was surprised by someone sitting in Severus's usual spot.

"Albus!" she said, startled.

"Yes, Lydia. I do occasionally come to the Quidditch."

He was smiling, but she supposed this was part of the plan. Severus on the pitch, Albus in the stands, and nothing would happen to either Harry or Lydia during the match from whomever was attacking either one of them. She was just beginning to relax when she looked down at the teams. Severus, unfortunately, looked perhaps in one of his nastiest moods ever, and she found she couldn't relax.

They'd barely set off when Hufflepuff got a penalty. In fairness to Severus, one of the Weasley brothers did hit a Bludger at him, not at the other team, but Lydia wasn't sure that was in the rules. Hufflepuff took and made the penalty, and Lydia had never felt worse for Oliver Wood.

"Oh, for Merlin's sake," Lydia muttered.

"I wouldn't worry too much, my dear," Albus said happily.

"No?"

"Not at all. Because I've just seen a little flicker of gold, and I believe I am not the only one."

Not already, surely. She couldn't recall the Snitch ever being spotted so soon. But just as she was about to say so, Harry jetted into a shallow dive. She held her breath, not because of the Snitch, but because he was barreling right at Severus. Severus turned only just in time for Harry to barely miss him, then pull out of the dive with a little flicker of gold in his hand, held up triumphantly. If there was one thing he'd inherited from his father, it was knowing how to do a victory pose.

"That was less than five minutes!" Lydia cried.

"You should come with me, my dear," Albus said softly. "Severus looks in a very foul mood."

She didn't need further excuse. She let Albus lead her down the stairs to the pitch. The players were landing, and Severus had already landed. Lydia saw Albus go toward Harry, still clutching the Snitch, but she went to Severus. He looked furious, paler and tenser than she'd seen him in years. He spat at the ground, and she stopped in front of him, pressing a hand to his shoulder.

"Someone might see," he said, almost in a growl.

"No one is going to care right now," she said. "Everyone's celebrating the game." She gave him a weak smile and said, "No one had time to hurt him."

"Just as well," he said.

"Why are you looking so cross, then?"

He glanced over her shoulder at something, then said, "I've set up a meeting with…with my suspect."

"Sev—"

"For later this evening. On the edge of the forest. Sometimes, Lydia, the best way to learn the truth is to watch their reactions when confronted."

"If he's the mastermind you seem to think he is—"

"I will not wait around for someone to kill you," he said, nostrils flared. "Among other possible concerns. He seemed reluctant to meet, but I believe I piqued his interest enough, and he did agree."

"So you'll possibly be late for dinner," she said, looking back at Harry, who was being congratulated by his classmates.

"Yes," Severus said, frowning. "Late for dinner."

Lydia was suspicious, but she didn't say so. Instead, she let Severus change, told him she'd meet him back at the school. She did a bit of reading, and when he was back, she accepted her tea like nothing was amiss. But Lydia was watching him, and a plan was forming in her mind.

There were several reasons she didn't want to go through with her plan. The first was that it was almost impossible that he wouldn't catch her. If anyone could see through a Disillusionment Charm, it had to be Severus. The second reason was that it was a little too reckless, a little too James-and-Sirius, and she was bound to get picked at for that, even if she could stomach it. And the third reason was that she hadn't been anywhere near the forest since Dalia, and she wasn't sure with the way her psyche kept playing tricks on her how being in such proximity would go.

But she had to know. If Severus was right, if somehow she was in danger from Quirinus, she needed to know. And she needed to know what Severus was going to do, how he operated. She'd let too many things slip past her without argument during school, during the war. She wasn't going to be totally passive now, even if all she had was listening.

Lydia was careful to keep a sturdy base layer of Occlumency, just in case. She didn't think Severus was suspicious, she it wasn't likely that he would skim her mind, but she couldn't always tell when he did, and he might even do it out of habit.

When it was time for dinner, Lydia went up like she was going to the Great Hall, but she ducked into a corner and Disillusioned herself when there were no students or staff to see her. She waited, then, patiently, for Severus to sweep past her. Quirrell must have already gone out, because she didn't see him, but she followed as quickly and quietly as she could on Severus's heels, slipping through the doors as he burst through them, before they had a chance to close again behind them. She recalled what Dalia had said to her, coaxing her down to the forest: no students to see them leave; everyone would be at dinner.

Lydia couldn't believe he couldn't hear her following. The sound of her breath and pulse in her own ears was deafening, much less how loud her feet must be on the grass. Severus picked up his pace when they hit the trees, and it became even harder to keep up undetected. She stopped as soon as she saw Quirrell, and she ducked behind a tree to take the most advantage of her spell. The greetings were soft, and Quirrell was shifting nervously.

"I d-don't know why you wanted t-t-to meet me here of all p-places, Severus…"

"I thought we'd keep this private," Severus said coldly. "Students aren't supposed to know about the Philosopher's Stone, after all."

Quirinus's voice was so soft, she almost missed it, but he mumbled, "Th-that's very true, b-b-but I—"

"Have you found out how to get past that beast of Hagrid's yet?"

Lydia could tell the method at once. Make it look like Severus knew everything Quirinus was up to, and if he was truly up to it, the protestations would fall away eventually. But if he wasn't, the innocence should ring true.

"B-b-but Severus, I—"

"You don't want me as your enemy, Quirrell."

Severus's voice was low, dangerous. He took a step closer to Quirinus, and Lydia held her breath.

"I-I don't know what you—"

"You know perfectly well what I mean."

There was a loud hoot from an owl, and Lydia had a strange feeling like someone was watching them, like there was someone else there, but no matter where she looked, all she could see was Severus and Quirinus.

"I want to know," Severus said, "how you expected Lydia to behave after your little bit of hocus-pocus." Quirinus stared back at him, perhaps more confused than he'd looked before. "I'm waiting."

"B-but I d-d-don't—"

"Very well," Severus snapped. His head was tilted slightly. Was she breathing louder? Did he know she was there? "We'll have another little chat soon, when you've had time to think things over and decided where your loyalties lie."

Severus put his hood up and strolled out of the forest. Lydia carefully followed him, not daring to look back over her shoulder at Quirinus, who was standing as still as stone where Severus had left him. Back inside the castle, Severus went into an empty, unused classroom on the first floor, and Lydia followed him in, curious. She was startled when he turned abruptly and tapped his wand on her head. She shuddered at the sensation like an egg cracked on her skull, as she became fully visible once more.

"You foolish woman," he said softly. "If I knew you were there, what makes you think he didn't?"

"You knew the whole time?" she asked, horrified.

"Charms were never your strongest point. He's clearly guilty."

"Of going for the Stone?" she said, frowning. "Maybe, although…. Well, I don't know. I wouldn't indict him on that alone. But Sev, I don't think he attacked me."

Severus frowned, obviously wanting to argue with her, but she put a hand up, desperate to tell him what she was thinking.

"Sev, there was someone watching you."

"Yes, I know. We need to work on your stealth—"

"No, Sev. I could feel someone else there. Not just me. I didn't see them, but…there was someone else in the forest with us."

He frowned, glancing back at the entrance hall.

"Students will be at dinner or in their dormitories," Severus said. He looked at his watch. "Yes. A member of staff?"

"I don't know who it was. But what if…?"

She shrugged. It sounded foolish in her own head, but if Severus was willing to believe that Quirinus was after her, perhaps it wouldn't seem so foolish to him. What if her attacker had followed them to the forest? What if that's who was watching them?

"If it was a separate person, as you seem to think," Severus whispered, "and if they were there, I find it unlikely. After all, this person's hallmark is being totally undetectable. How is it that you would sense it and not I?"

"Because you already knew someone was watching, so you weren't looking for someone else," Lydia suggested. "And I'm the only one who can smell that…that…something in our quarters."

"I still have no idea what that's supposed to be," Severus said with exasperation. "But I'm willing to concede it is possible. And if it did happen, and that person was watching, then all they've learned is that their identity is safe, that I suspect someone else." He paused. "I still believe it's him."

"I know you do," Lydia whispered. "Just…can we not sleep tonight?"

"Why?"

Lydia shrugged. She'd seen enough Muggle crime shows to know that the killer always came back to finish the job if they were threatened. Likewise, if they thought they were safe, they might fulfill their original goal. Either way, Quirinus or someone else, she didn't feel safe if Severus was asleep, not tonight.

He hesitated, but he did agree. They went to dinner, and Lydia found it uncomfortably easy to pretend like she knew nothing, to keep her walls up around her thoughts, to be cool and closed. After dinner, she made tea for her and Severus, to help them stay awake, and he settled by the fire with a book.

"If you read to me," she said, almost laughing, "I'll fall asleep."

"You find me so dull," he said.

"Your voice is soothing," she said. She sat on his lap. "So's the fire. And the tea, come to that." She rolled her eyes. "I don't know. I used to stay up all night sometimes when we were young. I don't remember how anymore."

"When we were children, it was from fear," he whispered. "The adrenaline. Perhaps sometimes adrenaline from excitement or focus when you were older. Study sessions, moments of inspiration. Tea, once upon a time, perhaps. I've always found a cold shower just at the time when sleep is starting to take over—"

"I'll keep that in mind," she said, knowing she sounded bitter. Severus just laughed, lit a few more candles, and told her about what he was reading.

A/N: So Lydia's keeping her seventh year students on track, Severus referees one of the shortest Quidditch matches in Hogwarts history, and FINALLY you know what the full sentence was that Harry half-overheard in the forest. Lydia still isn't so sure that Quirrell is the one after her, and Severus is even more convinced of it. Also, Lydia needs serious stealth lessons.

Right now I'm drafting August before the second year, and I'm super stoked because they're going to learn soon that Lockhart is going to be the new DADA prof, and I'm dying of laughter with how much fun I'm about to have with this. Even if I'm not a huge CoS fan, I get to write Sev RAGE about how underqualified this buffoon is and we're all going to enjoy it immensely, even if it isn't Sirius breaking out of Azkaban. I promise.

Review Prompt: If someone were actually going to give Lydia stealth lessons, and it can't be Severus (because he's the obvious choice), she's actually pretty spoilt for choice. Who would you choose?

-C