Snape had a third year class for his first lesson; Hufflepuffs and Slytherins. The Slytherins’ hair was still as bright as it had been at breakfast, but it would probably fade by the end of the day. They kept throwing venomous looks at Harry but he was too busy to notice.

It turned out one of Snape’s classes had over-run yesterday and the students had had to leave without tidying up. This meant that there were about twenty cauldrons which needed to be cleaned to Snape’s exacting standards. It was taking a long time.

Harry was still working at the last couple when the next class arrived. With it, appeared Fred and George Weasley. They tried to argue with Snape about whether Harry was really to blame.

“Professor, there’s no chance Harry did it-”

“Yeah, all he did two years ago was try to convince everyone he wasn’t responsible for all this ‘Hair of Slytherin’ stuff.”

Harry tried to choke down a laugh by hiding his head in the cauldron he was cleaning. He saw Cedric Diggory trying to hide a smile as well from the other side of the room. Snape wasn’t amused by the pun, and made some strong, sarcastic remarks about their potion.

It didn’t stop them.

“Don’t brush us off, Sir!”

“Just mullet over. Don’t bleach it from your memory.”

Snape turned away in disgust.

Fred leapt to his feet, with his hand up in the air. It was a surprisingly good imitation of Hermione.

“Wait, Professor, come back-”

Snape turned his head slightly.

“I moustache you a question!”

Harry couldn’t hold back his laughter, snorting loudly. Snape whipped back to him instead.

“Mr Potter, you are obviously not feeling challenged enough with your current task, since you have the time to listen in to my teaching. When you have finished that, you can begin to copy out the instructions for this potion. Four times should do the trick.”

“Misters Weasley,” he snapped. “Thirty points from Gryffindor for disrupting my class. And it will be another thirty if you do not complete your potion to my satisfaction.”

The Gryffindors moaned a bit, but they were obviously used to the twins losing house points. Angelina Johnson did hit Fred over the back of his head, but overall they didn’t seem to mind very much. The pair earned enough points for other things, usually quiddich.

The potion the class were brewing had long and complicated instructions. Harry had to start shaking out his wrist between sentences somewhere in the middle of the second copy.

When the sixth years left, Snape waited a couple of minutes for Harry to finish his last set of lines. On the way up to lunch they met some of the older Slytherins who were heading up from their free period. Snape frowned when he saw them.

“Mr Wilson, is there a reason why your hair has not begun to fade?”

Wilson scowled back. “It started to, Sir. But it has become worse again.”

“And did none of you think to cancel the charm which was causing this? You have covered this in NEWT Charms, have you not?”

The seventh year looked embarrassed. “I didn’t think, Sir.”

“Evidently not. Potter,” Snape beckoned. “You will come with me while I fix your mess. The rest of you, get to lunch.”

Harry was dragged back down to the common room entrance. Snape began to cast spells around the wall concealing the door. One caused a yellow shadow to appear, a sort of thin mist. It hovered above the entrance at about six feet above the flagstones. Another wave of the wand and the shadow dissipated and Harry knew the spell had been disarmed.

“There is to be no more of this, Mr Potter.” Snape said sternly. “Or I might require you to move into the Slytherin dorms instead of my isolation room.”

The Slytherins would kill him if he had to sleep in the same room as them.

“Or I could always extend the grounding charm.”

Then Snape would kill him.

“You have left no other little surprises, I hope?”

“No,” Harry said, sullenly. Snape raised an eyebrow at him. “Really, I haven’t. There’d be no point in me not telling you. You’ll just blame me for anything that happens anyway.”

The Slytherins who hadn’t returned to their common room were looking almost normal now. There was only a subtle difference in dark hair, it was the blonds like Malfoy who still looked a bit seasick.

Harry didn’t speak to anyone at lunch. The Slytherins weren’t keen to talk and Snape was perfectly happy pretending Harry didn’t exist. When Harry saw Professor McGonagall approaching them, he clambered off the bench to speak to her. Instantly, he had the strange sensation of being pulled backwards, as if he was standing on one of those flat escalators that muggles had in airports. It was pretty hard to keep his balance.

McGonagall smiled at the look of panic which flashed across Harry’s features. Snape glanced up from his lunch too, irritated. Apparently Snape could tell when Harry moved too far away from him.

“Mr Potter,” McGonagall said brusquely. “I have fashioned some questions which should allow you to cover the material you missed this morning. I will mark it for you if it is returned by curfew tonight.” She handed Harry a few sheaves of parchment, which he gaped at. “Mr Weasley and Miss Granger were distressed this morning when you did not return. You might wish to have a word with them.”

Harry looked over to the Gryffindor table, where his friends were watching with interest. He waved to them and they returned the gesture with vigour.

“Thanks, Professor,” he said. “If Professor Snape ever lets me stop cleaning, I’ll get right on it.”

“Do not exaggerate, Potter.” Snape drawled sarcastically from right behind Harry’s ear. “I did not make you clean cauldrons all morning, you were doing a sterling job writing lines.”

“Sir,” Harry said a bit later as the hall was emptying. They were two of the last people at the Slytherin table. “Can I get hold of my schoolbag? I haven’t got any quills or anything, and I need my transfiguration textbook to do this work.”

Snape smirked, “That is an excellent idea, Potter. Let us go now.”

Snape stood abruptly and Harry, who wasn’t ready for the sudden move, was dragged up from his seat after him.

From the man’s usual demeanour, Harry had expected Snape to ask another Gryffindor to bring it down. He definitely didn’t think they would just go up and get it. Harry was forced to almost jog after the potions professor. The man didn’t seem to take any notice of how far behind Harry was, and the boy kept tripping over his feet.

The Fat Lady sniffed haughtily when Snape gave the password to the Gryffindor common room. Harry was disconcerted when Snape moved to climb in through the portrait hole.

“Sir, wait, you’re coming in?”

“You can hardly go by yourself, Potter.”

“But, Sir! We could just shout for one of the others-“

Snape just gathered up his robes and stepped through. “Better to keep them on their toes.” He disappeared.

“Neville is going to kill me.” Harry muttered, hurrying to follow.

Sure enough, when they entered the fourth year boys’ dormitory, Neville took one look from where he was sprawled on his four poster bed before emitting a loud squawk and falling off the other side.

He emerged seconds later, red faced. He muttered something unintelligible before disappearing down towards the common room.

Snape snorted.

Harry frowned up at him, “You don’t have to be such a j- “he cut himself off quickly. “So mean to Neville. He tries his best. You should see him in Herbology.”

Snape arched an eyebrow.

“Well, maybe you shouldn’t. He always gets far worse whenever you’re around.”

“Potter, collect your bag before your house sends a rescue party in here.”

Harry did so, stuffing some of his robes in there for good measure. He grinned, the Gryffindors, after their initial panic, had begun to look like they were plotting a revolution. It would probably be for the best if they left before his housemates barricaded the doors closed.

“What class are you supposed to be in now?”

Harry looked up at Snape, incredulous. Was the man making small talk?

“Defence with Professor Moody. We’ve been doing the same spell for about two weeks though, Sir, so I’m not missing much by not being there.”

“And what is it you were doing? Surely it cannot take a whole class this long to grasp a fourth year concept? Even Wingardium Leviosa can be learnt within two weeks.”

“We aren’t learning the spell, Professor.” Harry laughed. “We’re learning how to throw it off.”

“What are you babbling about, Potter?”

“He’s trying to get us to be able to throw off the imperius curse. He’s always making us do stupid –“

“He’s doing what!?” Snape snarled. “The imperius? That is a strong accusation, Potter. Even Moody is not that dense! The man was an auror for Merlin’s sake.”

“He said he had Dumbledore’s permission.” Harry said, taken aback by Snape’s violent reaction. “He’s just making us do dances and gymnastics and animal impressions and stuff. It’s a bit embarrassing but he’s doing it to everyone. And he’s right isn’t he, Sir? It’s got to be better if we know how to throw it off.”

“It is an Unforgivable Curse, Potter. The ministry doesn’t care if you use it to make someone bake cakes, it is still illegal. I will have to speak to Dumbledore. The spell is far too easy to abuse. If it was me-“

“But you do teach potions.” Harry pointed out. “I get that it’s usually a pretty bad thing, but at least he’s actually helping us with defence. It would be a bit dodgy if you started using it on students.”

Snape ignored him. Harry just shrugged. Snape would talk to Dumbledore and the Headmaster would check everything was alright. That was what Dumbledore did, he fixed everything.

Snape cleared his throat as they descended through the green door into the dungeons.

“So, can anyone free themselves yet?”

Harry grinned, “I managed a couple of times the other day, but that’s it for the Gryffindors.” He waited and Snape grunted in response.

“Oh, and Neville managed it too.”

Snape spun around, searching Harry’s face to detect the lie there. Harry was delighted by the look of astonishment when Snape realised he had been telling the truth.

This lesson, Snape had him sit at the front desk, with his back to the class that was being taught. Harry had his Transfiguration work to do and it was a horrible mass of calculations. He chewed on the end of his quill absent-mindedly as he searched through his textbooks, trying to work out the next step of the problem.

“You do know that isn’t a sugar quill, don’t you?”

Harry turned to look at the first year along the table from him. The kid had one elbow resting on the bench with their hand cradling a pointed chin. They were neglecting their potion to stare intently at Harry.

“Uh, yeah. I didn’t really notice.” Harry mumbled. “I’m not actually eating it, you know.”

“It’s gross.” The kid informed him.

“Thanks…”

They stared at each other for a moment.

“My bench partner’s ill today. I’ve got to do this by myself and I’m rubbish at it.”

Harry pointed out that it might help if they actually payed attention to the potion. The kid just shrugged.

“I’m no good anyway. It doesn’t help if I watch it or not. Usually I just try to follow what someone else is doing.” They pointed to the table behind. “I’m waiting for him to do something, I reckon I’m at about the same stage.”

Harry blinked, “Are you joking?”

The child frowned, offended. “Look, forgive me if I don’t take advice from someone who eats feathers-“

“Look, your potion is green, right? You see how there’s steam coming off yours?”

He waited for the first year to compare the two.

“Right, the bloke behind us has a red potion, and it’s not got any steam. See that?”

“It’s not steaming, but it’s the same colour. There can’t be too much difference, mine is probably just a bit hotter.”

“Temperature is important in Potions!” Harry blurted, “Like, very important. Have you noticed yours is beginning to spit, by the way? That isn’t a good thing. It’d probably be for the best if you stopped that. And secondly, his potion is clearly red.”

The kid sighed and turned the flame under his cauldron down a little. “Happy?”

“No…” Harry leaned over the desk to look at the instructions. “Look, it’s supposed to be scarlet right now.” He tapped the right line on the page.

“It is!” The kid said.

Harry stared for a moment, a thought forming slowly in his mind. It seemed pretty unlikely, but unless the kid was totally blind…

“Are you colour blind?” he asked, bluntly.

“I’m not blind!”

“I didn’t say you were. I said colour blind, and it’s different. It just means you can’t see some colours the same way. Look, add an ounce of that powdered moonstone- that should calm it down a bit.”

Harry watched carefully as it was measured out. He felt eyes on him suddenly and somehow knew Snape was watching. He didn’t look up. Hopefully, he could fix the potion a little and then get back to those stupid mass and volume calculations for McGonagall.

“Right, now add four of those scales. Those green- sorry, the little ones. That’s right. There you go.” He smiled, “That’s it red now. The colour doesn’t matter for the rest of it, but if you want me to check, just ask.”

The first year looked a bit irritated. “Why do you care anyway? I didn’t ask you to look. And now you’re telling me I’m blind or whatever, and I’m not!”

The kid had become a lot less friendly very quickly. A far cry from the child who had started the conversation.

Harry tried to smile disarmingly, but he felt a bit like Lockhart, so he stopped. “Look, honestly I didn’t want to get blown up by that potion. And who knows, wizards made that creepy eye for Moody. Maybe they can do something about colour blindness too.”

“Indeed they can.”

Harry jumped right out of his seat.

“Professor Snape, I was just…”

“I know exactly what you were ‘just’ doing Potter. Fawley, thank Mr Potter.”

“Thanks a bunch,” The kid muttered.

“Since Mr Potter has rescued your potion, and saved your grade today from being ‘Troll’ standard. You can spend the time this evening which you would have spent rebrewing this potion, learning another.”

“But Professor Snape!”

Snape held up his hand for silence. “I will show you the potion used to help with colour blindness, if that is really your problem. The potion only works for a few days, so I will supervise your brewing for two weeks.”

“What if I’m not? What happens if I take it and I shouldn’t?”

“Then you might need sunglasses for a couple of days. And you can brew this potion for the rest of the fortnight instead.”

Fowley scowled, obviously not happy with either option.

“Now finish that, you only have twenty minutes left.” Snape glanced at Harry as he stalked away to deal with a struggling Ravenclaw. “Potter, I want a word with you after class.”

Harry rolled his eyes and settled back to his Transfiguration work. “It’s not like I’m going anywhere.”

“What was all that about?” Snape demanded, arms folded tightly.

“What was what about?”

“Are you colour blind?”

“No? Why would I be?”

Snape huffed. “Fowley is a Slytherin, Potter. I know you noticed that. What did you expect to get out of helping? You know I can’t get rid of you until Monday. Helping one of my Slytherins isn’t going to make me go easy on you.”

“It wasn’t me I was worried about! Honestly, I thought you might jump on the kid if they kept going like that. I was pretty happy that it didn’t blow up all over me. I didn’t see you anywhere near when it started to foam up!”

Harry was indignant. Snape always suspected him of having the worst motives. Was it so strange that Harry might just be being nice for the sake of it?

“Potter, I was watching. As a fourth year, you should be capable of calming a draught a little, and of correcting simple errors in potions. What’s more, you saw a very similar mistake when you brewed this exact potion with Mr Longbottom. You did cope with it. What more did you expect me to do?”

Harry scowled. “I don’t know. You didn’t have to give the kid detention over it though.”

“Detention?” Snape looked perplexed. “I didn’t give Fowley detention.”

“You did. You said they had to come tonight and for two weeks.”

Snape sighed and looked up to the ceiling. “Yes, to Potions Club. Fowley is already a member. Not a very good member, but alright when brewing in a group.”

“There’s a club for potions?” Harry asked.

“Yes,” the Professor said, as if it was the most obvious thing in the world. “For the past ten years. It’s on Tuesday’s and Fridays.”

“Oh, that’s why I’ve never heard of it. Who’d want to do potions on a Friday night, you’d have to be mental.”

Snape looked vicious.

“Sorry, Sir…”

“Your friend, Miss Granger, for one.”

Harry was unimpressed, Hermione would go if the club was held at five o’clock on a Sunday morning.

“Mr Diggory, from the Hufflepuff quiddich team, you have met? I believe he beat you in a quiddich match last year?”

Harry scowled, they had only been playing the Hufflepuff team because Malfoy had played up his injury to get out of the match.

“The Weasley twins come sometimes, on the rare occasion they can control themselves.”

Harry gaped, “Fred and George go?”

“Indeed. They work on some… intriguing concoctions, to say the least.”

Harry thought of the ton-tongue toffee’s and privately agreed with Snape.

They both heard the sounds of quiet talking outside the door. Snape gestured for the Gryffindor to sit down, before sweeping out of the door to bring in the next class.