Harry had never had a wristwatch, so he was very glad there was a clock in the common room, on the mantelpiece in front of a mirror.

The mirror itself was large and old, made in one piece out of silvery metal and tarnished at the edges, where polish gave way to an intricate frame. Harry first decided that he liked it when he noticed that Draco was too short to properly check his appearance in it before going out, to Draco's great frustration. For Harry, the mirror reflected the shimmering of ceiling lights whenever he took a break from poring over his homework, and that was enough.

And now, as he stood in a dim, chilly corridor, in front of the Potions classroom door, Harry distinctly missed the lights and warmth of the common room. The door was locked, not helping his dwindling confidence. Perhaps, he was expected somewhere else? Perhaps, he was late by some trick of time and space? After all, the only clock available to Harry remained standing on the mantelpiece a few levels down.

He reached into his robe pocket hesitantly. No rogue wand-waving in hallways, Harry thought in Deena's voice. She had given him a big piece of her mind on earning a detention, too. He sighed.

But then, one of the charms that Theo used was really harmless. And simple.

After the first couple of tries he conceded that it wasn't very simple. While the charm seemed to work, it was showing him something different on every try and, so far, nothing that Harry could make sense of. Why on earth “684269051”? He tried again.

Just as the glow of “18:45” faded before his eyes, a voice close behind him said, “Why, if it isn't Mr Potter, potionmaker extraordinaire.”

Harry's reflexes couldn't decide between jumping in surprise and freezing in place, so he used the moment to stuff the wand back into his robe pocket.

“G-good evening, Professor. I was just...”

“...Waiting for me, no doubt. Potter, don't bother; I have eyes, and they serve me well.”

Severus opened the door and motioned Potter to come inside. He decided to disregard the time-telling attempts, which were, in fact, pretty decent for a Muggleborn barely a week into classes; Filius would've been ecstatic before taking points. But Flitwick had missed his chance, and Severus wouldn't do the job for him. Now, if someone tried to brew a potion out of the proper facilities...

Harry sat on a stool summoned to the front of the classroom and watched warily as the professor dropped the sheaf of parchment he'd been carrying on his table and took the usual place behind it. He wondered if the spellcasting had just turned his punishment worse.

“Now, Mr Potter, do you remember why you are here tonight?”

“Yes,” he said, dropping his gaze to his lap. “Yes, sir.”

“Backtalk is not an acceptable behaviour during class. ‘It’s called One Thousand Herbs and Fungi for a reason’ is by no means an acceptable answer to a question.”

The boy’s face scrolled through red and white in a quite satisfactory way, but the fight hadn’t left him entirely.

“I’m sorry, sir. I’m sorry, but it was true! How should I have… known...”

“Potter! Look up!” Severus’ fingers connected with the table edge sharply. “If you cannot tell one ingredient from another, then you don’t go guessing randomly! And you don’t — talk — back. Is that clear?”

Receiving an affirmative, he continued. “Were you representing any other house, I would’ve brought the points total into negative and be done with it. However, you are who you are, and your Muggle habits…” Severus trailed off, as another thought overtook him. For a couple of seconds, he merely looked at Potter, then finished calmly, “…are of no use now. If you wish to fight for yourself, this is not a way to go about it; and a wrong target indeed.”

He stood up to give instructions for mutilation of some simpler and nastier ingredient stock. Potter obeyed wordlessly.

Severus settled into grading the third-year test papers, glancing up now and then to check on the boy's progress. He quickly recalled why he had put off dealing with that particular pile until late into Saturday.

~SS~HH~SS~HH~SS~

By the bottom of the second jar, Harry was cutting up the greenish-grey ragworms quickly and methodically. He'd got the idea of how not to mash them with his knife, so he let his mind drift and the feeling of intense shame — slowly dissipate. The professor didn't seem too angry with him, but Harry wasn't sure. Also, he was somewhat angry with himself.

“So, Mr Potter,” he heard suddenly, “tell me: have the Potions practicals been meeting your expectations so far?” Sarcasm in the question rang clear.

Harry managed to wipe his itching nose on a sleeve and shrugged.

“I dunno. You said potions are almost like non-magic, but in reality it's the opposite.”

“Indeed?”

“Well, sir, you see, people don't usually wave pointy sticks over needles, whether expecting them to turn into something or not. So it's doesn't seem weird when they do turn into matches; just different. But I cut up stuff and put it together in pans over fire all the time, and nothing like brewing glory happens, ever! Even accidentally, as I'm a wizard and all.”

The professor listened with a peculiar expression on his face, which Harry found almost bird-like.

“It feels like a giant empty space instead of things I should know about magic,” he added, gesturing around the dungeon with the knife. “And I don't want to feel like that.”

“Does your empty space, Potter, contain at least the instructions for the potion you've failed upon facing the unknowable Universe?”

“Of course,” said Harry, a touch peeved. He had moped over the book for a while.

“Oh, really? Then clean the table and be prepared to try and brew glory. Or to try and brew a passing grade. One way or another, you will remake the assignment, and I won't help you; the glory will be all yours.”

Inexplicably, the boy was grinning and nodding in a way that was becoming familiar. Severus suppressed a pang of premonition.

“You know where the supply cabinet is. And I trust that you will manage to recognize the necessary jars — this time. Get to it.”

Potter looked about to dash across the room, when Severus added, “Just a moment. Give me your glasses.”

And back to his thankless work. Frankly, Severus didn’t need a test to know that the students’ grasp on the subject invariably dropped to absolute zero over summer; but it made for excellent scare tactics. He looked at the parchment in his hand. Then again, there were the Weasley twins. The only scare tactics for them involved contacting Mrs Weasley, which made the torture mutual and the whole idea mostly not worth it. He put the parchment aside and started on the Hufflepuff bunch.

He was contemplating a particularly wild flight of ignorance, when something diverted his attention. Severus dropped his quill, crossed the floor in two strides and pulled Potter back from the workbench by the scruff of the neck.

“Never poke your nose into a potion, you foolish brat! Neither when it boils, nor when it is complete!”

Potter looked up at him with a startled expression and mumbled something to the effect of an apology. Severus didn't intend to let him go so easily.

“And why, do you think, does this rule exist, Mr Potter? Answer.”

The movement of his eyes told Severus the boy tried to recall the reading.

“I take it that you haven't paid any attention to the preface of your textbook, in which the matter is explained at some length.” At the length of three paragraphs on the eighth page, in between piles of the author's self-righteous blabbering, Severus added mentally.

In fact, Slughorn's assigned textbooks along with his lesson plans had been making into the top of Severus' teaching hate list from the day one, right below some of the more idiotic Hogwarts students. However, with the young professor's customary absence of good luck, changing any and both required going through an approval procedure, and the approval procedure required more paperwork than a master's thesis in Potions — for each of the seven years of study.

“No matter now,” he told Potter. “To study Potions, one should possess a basic reasoning ability. Think.”

Harry looked into the cauldron again. Despite the smell, the liquid reminded him very much of a stew in Aunt Petunia's shiny pan.

“Because, well, a hair could fall in and spoil that?”

“Good.” There was an infliction of surprise. Later, Harry would wonder which part of it was surprise at the professor's own choice of adjective. “Even though potions you brew at this level wouldn't be spoiled by a minor organic matter contamination.”

“So — it doesn't really matter if I'm doing it now?”

The professor gave him a long emotionless look, which Harry recognised and didn't like any better this time around. It probably meant that —

“Potter, unless you are set on poisoning yourself, you don't want to get a lungful of decomposing ingredients. And even if you are, there are a lot of quicker and less issue-prone ways. Most of all, I hoped you would remember one Neville Longbottom, your hapless peer.”

— he was missing something awfully obvious.

“I don't plan on blowing it up,” he mumbled without any real conviction.

“We'll see.”

After that, Professor Snape stepped back, leaned his hip on the table next to Harry's and nodded at him to continue. He never returned to his seat, watching like a hawk and commenting every couple of minutes — more often on Harry's mistakes; although at times he idly unfolded a comment into an explanation, which was interrupted by the next mistake.

While struggling to both process the words and pay attention to the potion, Harry found that he wasn't half as anxious as he'd been during the lesson, or just now — working alone. It felt nice.

~HH~HH~HH~HH~HH~

“Theo, Theo, Theo —” Flop.

Theo looked up from his book reluctantly. “All the extremities intact. You are lucky.”

“Uh-huh. I just cut up some sandworms. They were kinda rainbowy and fat, and full of this blue slimy stuff —”

“Eww, stop it! I just don't want to know.”

“But they're... pretty, sort of. And then I made it... Not to blow up.”

Silence. Theo put the bookmark back in and closed the volume.

“Harry? Made what?”

His Friend-Who-Lived didn't manage to get under the bedcovers as much as to tangle the covers around himself, grab the pillow and give up the struggle.

“'rythin'... M'glasses, look...”

Theo leaned over to Harry's nightstand and picked up the item gingerly. What? Oh. No tape, no scratches. All intact.