Remus watched Harry out of the corner of his eye as he went through the practical exercises with Ron. His mind kept going back to the image of Snape making his way across the Entrance Hall. The Potions Master constantly smelled of the potions he brewed, so much so that it almost always obscured his own scent. Which is why the werewolf hadn't recognized it until the previous day. It had been years since Lupin had encountered Severus Snape without his cloud of potion fumes. Even when his own scent wasn't overpowered, their smell had still lingered. But Remus had finally identified Snape's as the phantom scent of his memory. The scent which reminded him of Harry's.

"He's mine, Remus." James' voice came back to him as he tried to piece together the truth which now faced him. His friend had been able to say more with his tone or demeanor than most people could express with words. Like the day Remus had first held Harry, the man's conviction had -

Remus could have kicked himself. He had missed a good part of what had been communicated to him that day. James' words had been the proud declaration of any father: "He's mine." But what James had been actually saying was, "I know you aren't stupid, but I need you to believe this."

And he had. For thirteen years.

His eyes sought out the boy as everything fell into place: James' unforeseen engagement and marriage to Lily, her unease during those first few months, their odd relationship, the wistfulness that often crossed Lily's features as she watched James with her child, and so many other small pieces that Remus had failed to associate with the puzzle to which they belonged.

Now, the picture was clear. James had known that Harry wasn't his, which meant that the ruse must have been meant to keep the boy and his mother safe, and quite likely, his father to some degree as well.

Lupin heaved a sigh as his mind finally registered the green eyes gazing curiously back at him. Too bad it wasn't enough, he thought sadly.

- - -

There must be something in the water. Everyone – or at least, a good number of people – had been acting strange. First, there had been Snape's staring, then Madame Pomfrey seemed to become a bit odd overnight, now, there was Remus. Harry didn't know what to make of it. He couldn't recall Remus ever giving him that look before. It reminded him of the look he often got from strangers when they found out he was Harry Potter. It was... disconcerting.

Speaking of disconcerting, and adding to Snape's growing list of oddities, was the detention he was currently serving. Dissecting full vats of dead toads or scrubbing cauldrons, Harry had come to expect, but not only were the ingredients he was currently preparing not slimy, Snape had specifically shown him how he wanted it done!

The teen was puzzled. He wasn't even preparing bulk amounts of the ingredients he'd been set to work on. In fact, he was probably only making enough for one or two potions. Furthermore, as far as he knew, half of them weren't even used in class. Of course, they could be for an upper level class, but that did not account for the sparse quantity.

Bicorn horn, he recalled, they had used in the Polyjuice potion they had illegally brewed the previous year. For that potion, it had been powdered, but Snape wanted it coarsely ground. They had lionfish spine in their potions kits, but Harry had never seen their sun-colored scales before. Just as confusing, perhaps, was everything else – all common ingredients that they generally prepared for themselves in class.

Harry shot a quick look over at his teacher where the man was dutifully marking essays. He was starting to suspect that the Potions Master was using him to prepare for a potion he hadn't been able to get to. It was a bit irritating, actually. With that evil smirk the man had given when he pronounced his punishment, Harry had been envisioning something truly horrific – dissecting dead carcasses, at the least. This, though... this was practically dull! Since when had the man taken to trying to bore students to death when he could give most heart failure with a single sneer?

Snape was not oblivious to the surreptitious glances Potter sent his way. He found the boy's confusion rather gratifying. The man had fully intended on making the brat start out with something vile, but had opted for having him prepare the ingredients for the Abbas Potion instead. He could then make the boy brew it himself during his detention the following evening. The cauldrons could wait. He wanted this order of business out the way as soon as possible.

It was almost curfew when he finally dismissed the boy. Severus approached the table the student had been working at, hoping that most of the ingredients wouldn't have to be prepared all over. To his surprise, everything was exactly as he had specified, the bicorn horn ground and lionfish scales sliced just as he had shown the boy. Perhaps being a bit more demonstrative during class would bear salutary results with other students? It had honestly never crossed his mind.

Putting everything away, Snape locked his classroom and office and made his way back to his quarters. Soon, he thought, soon, I'll know for certain. A niggling voice in the back of his mind reminded him that he already had the word of a highly trained mediwitch on that count, but Snape told it to keep quiet.

- - -

Hermione and Ron looked up from the table as the portrait hole opened and Harry entered the common room. Abandoning their homework, they hurried to greet their friend.

"How'd it go?" Hermione asked.

Harry stared at them a moment before answering. "He had me prepare ingredients."

"You mean, like cutting up rats?" asked Ron.

"Like I was preparing to make a potion. And he showed me how wanted to do some of it."

"When you didn't do it the way he wanted?" Hermione wanted to know.

Harry shook his head. "Before I started. He showed me exactly how he wanted me to grind the bicorn horn and slice the lionfish scales."

Ron gaped a moment. "Who was he, and what did he do with Snape?"

"Ron!" Hermione exclaimed.

"Hermione, Harry just returned from detention, with Snape, in one piece," the redhead pointed out.

The girl frowned and turned back to Harry. "It doesn't really sound like his usual detentions," she admitted.

"You're telling me," Harry said. "I bet he'll come up with something nasty to make up for it tomorrow."

Ron grimaced sympathetically. "Sorry, mate."

- - -

"Enter." Severus looked up as the door to his office opened to admit a petite, silver-haired mediwitch. He suppressed a sigh. "Poppy," he greeted her neutrally, setting his quill aside.

"Have you made your potion, yet?" Poppy demanded.

"That is none of your business," said Severus.

"Incorrigible man," the woman muttered under her breath. "Are you planning on telling the boy?"

"Perhaps. If there is anything to tell."

Poppy planted her palms on his desk, leaning forward to glower at him. "You are unfailingly stubborn, Severus Snape," she intoned, "so I am going to be perfectly clear: I did not make a mistake. Harry is your son. He has the right to know this. If you won't tell him, I will."

"You have no right!" Snape snarled, rising to his feet so quickly that his chair toppled over.

The mediwitch straightened to glare back up at him. "He is a student of this school. As such, his well-being is my business. I don't imagine he'll be any more thrilled by the news than you are, but it will be far better if he is told outright rather than left to find out on his own."

"I believe you are overestimating the boy's intelligence," the Potions Master scoffed.

"And you're insulting it," Pomfrey told him curtly. "Harry's a bright boy, Severus. He's Lily's and your son – he's bound to be." The witch whirled about and made her exit, pausing at the door to say over her shoulder, "I mean it, Severus. I will be speaking to him. I suggest you get to it first."

As the door closed behind her, Snape righted his chair and lowered himself into it. His gaze drifted to the door leading to his classroom where the child in question would be serving detention in a few hours. Part of him knew that Poppy was right, but another part of him just didn't want the boy to know.

- - -

"Sir?"

"Do you have difficulty hearing, Potter? Or are you incapable of understanding simple directions?"

"No, sir, it's just..."

"'Just' what, Potter?" Snape demanded, raising a sardonic brow.

"Nothing, sir," Harry mumbled, averting his gaze.

"Good. Get to work." The man returned to his desk, where he seated himself to grade papers. Or pretend to, at least, as he spent far more time watching Potter out of the corner of his eye.

Harry turned his gaze upon the parchment Snape had laid out on the table. On it was a potion that his professor wanted him to make. The list of ingredients included all of those he had prepared the previous evening. If he'd been slightly confused, then, he was utterly confounded now. He began to wonder if the Potions Master was under Imperius. Maybe that was why he'd been acting so strange. Or perhaps, it was someone taking Polyjuice and they were doing a rather poor impersonation.

Giving himself a shake to rid his mind of wandering thoughts, Harry set to work, careful to heed each and every step. As he did so, the boy couldn't help but note that Snape hadn't written the name of the potion on the page and it certainly wasn't one he had seen before. In fact, it appeared more difficult than those they were currently making in class. Not that Harry found it too complicated, really – just an odd assignment for detention with Snape.

Severus had to will himself to remain in his seat. It would have been so much easier on his nerves to hover over the boy's shoulder as he worked, but that would have ruined his efforts to appear disinterested. It wouldn't do to look as though he wanted the brat to succeed at his task, even if that was exactly what he wanted. Time crawled.

Harry's finger finally rested on the parchment beside the final step. 'Potion should be a light ash-gray color,' it read after directing him to add lacewing flies. Peering down at the soot-colored fluid, the boy was startled to find Professor Snape standing directly across from him when he looked up again.

"May I?" The man held out a hand for the stirring rod and, wordlessly, Harry gave it to him. He raised the implement from the brew, watching the liquid drip from its end. "Consistency is good," he noted clinically, "Color is as it should be. Well done, Potter. Pity you cannot do so well in class."

Harry opened his mouth to respond, but uncertain as to whether his teacher had just insulted or complimented him, he closed it again, looking mildly baffled.

Smirking in amusement, Snape drew a vial from the pocket of his robes and handed it to the boy. "Add this, Potter," he directed.

"Yes, sir," said Harry, taking the vial and the stirring rod. His instructions didn't call for any other ingredients, but he wasn't about to argue. He looked at the contents of the small glass tube for a moment as he removed the stopper. It was a viscous, crimson fluid. The boy glanced up at his professor briefly, but made no comment as he poured it into his cauldron. The potion turned blue.

Snape extended a small silver knife towards him. Harry slowly took it, directing a questioning gaze at the older wizard. "Sir?" he questioned.

"A small cut on your finger should suffice, Potter," the man said in answer, indicating for him to do so.

Harry stared at his teacher for a moment before finally deciding the man was serious. He winced slightly as he drew the blade across the tip of his left index finger. Holding his hand over the cauldron, Harry allowed several drops to fall into the potion before Snape grabbed his wrist. With a low murmur, the man healed the cut and immediately released him again.

Snape returned his attention to the Abbas Potion. He couldn't say why he had healed the boy's finger when he could have just as easily done so himself. He didn't really want to analyze it. The brat was staring at him, he could tell, but he kept his gaze on the potion as it changed from a pale blue to a pearlescent black.

"That will be all, today, Potter," he spoke quietly, tone empty of emotion. "Return to your dorm."

"Sir, what..?" Harry began, but was interrupted by Snape.

"I told you to LEAVE!" he nearly shouted. He faltered as his gaze met a pair of startled green eyes. Lowering his voice, he continued firmly. "Just... leave. Now."

Without another word, Harry gathered up his belongings and left.

Snape's hand rested on the lip of cauldron, an odd sensation spreading through his chest. No longer could he persist in his futile denial, having ripped all uncertainty away himself.

"He's mine," Severus murmured quietly. "Potter... Harry is mine." As he continued to stand there, Poppy's words echoed through his mind: "How will you make it up to him?"

- - -

Harry lay in his bed, staring up at the hangings in the dark. His detention – if it could really be qualified as such – kept playing through his mind. He had relayed the experience to Hermione and Ron, but none of them knew what to think about it. Hermione had concluded, as Harry had already, that the potion was making some sort of comparison between his blood and that of someone else. They just didn't know what – or who, for that matter. After asking an absurd number of questions, Hermione had vowed to look the potion up in the library the following day. Harry and Ron had every confidence that she would succeed.

So, now, Harry lay wide awake, listening to Ron snore and Seamus mumble in his sleep. Something about Snape's response was bothering him. He'd almost seemed... shocked, perhaps. Maybe resigned. It was hard to tell as Snape seemed to lack many of the facial expressions most people exhibited.

Of one thing Harry was certain: anything involving his blood that elicited a response from Snape couldn't possibly bode well.