Harry didn't seem quite as angry with him as the twins but he was irritating him in a different way, being far too concerned about Lupin and the reason for his absence, demanding to know what was wrong with him.

Albus had forbidden him from outright informing anyone, including his own children, of Lupins affliction but that didn't mean he couldn't play him at his own game and drop plenty of hints.

Diverging from Lupins lesson plan Severus had spent the class teaching them about werewolves and he had thought that with that and the fact the boy was aware his father was brewing wolfsbane for someone on the Headmasters orders, that he might have put two and two together. Unfortunately however, despite him studying astronomy and even with Severus having made a point of remarking on how bright the moon looked after dinner last night he didn't seem to have made the connection.

He could have set them homework, an essay on the identifying characteristics in werewolves would surely have prompted realisation in at least some of them but he had been distracted, still half focussed on trying to work out what was going on with the twins, and the idea didn't occur to him until he was already on his way back down to the dungeons after the class ended.

He was reminded of this disappointment again later when he saw Harry speaking with the Twins before dinner. He knew that their misbehaviour could at least in part be attributed to the unexpected trip home last night and he would have felt vindicated if the children could realise the threat he had wanted to avoid.

As it was he was sure that they would try to make out that he was the one in the wrong and that their brother would be convinced to take their side, leaving him once again an outsider in his own family.

As it turned out however Harry did not side with his brother and sister on this one.

Concerned about how upset they were about the whole messed up family situation, he had purposefully sought them out before dinner to check on them.

He was hoping that returning to the company of their new friends might prove enough of a distraction to stop them obsessing over the what ifs but if not he wanted to make sure they knew that they were not alone.

What he most definitely wasn't expecting though was for the Twins to inform him that they had earned themselves a detention.

"For what?" He asked, shocked. Thinking one of the teachers might have been forced to punish the entire class for something or other, he loved the Twins with all his heart but having grown up under the stern potion masters rule they were incredibly straight laced and not at all likely candidates for detention.

Evan Grinned, "I tried to blow up our potion!"

"You didn't? On purpose?"

He nodded.

"Evan no!, Why?"

Evan shrugged but then highlighted the fact that their father would have to spend the evening with them now.

"You know if you had wanted to see him that much, you could have just gone down to his quarter's. Harry said gently, "You shouldn't have blown up your potion, you could have seriously injured someone.

"You might be able to get away with just inviting yourself down to his quarters. He would have sent us away." His brother replied bitterly.

Harry started to refute this, their father treated them exactly the same, it was just that Harry was more inclined to approach him, but Lily interrupted to point out that they didn't even know where their fathers quarters were so couldn't have went to visit him even if they wanted to.

"They're down in the dungeon, hidden behind his office" Harry informed them, thinking this should have been somewhat obvious, all of the teachers quarters were hidden behind their offices.

"Really? But it's so dark and horrible down there. No wonder he's always in such a bad mood."

"It's not that bad down there, he has a big window that looks out into the lake. It's kind of cool the way the light ripples through the water and you can see all the fish and sometimes even other creatures swimming past.

"I really wish we had had our dinner down there yesterday, we would have gotten to see it then." Lily said sadly.

Harry put his arm around her, he knew why they were upset and he wanted to comfort them but he still couldn't believe that they had deliberately blown up a potion, it was so unlike them! "Does Father know you did it intentionally or does he think it was an accident?" he asked.

"Oh he knows." Evan said, still sounding rather proud of himself.

Harry frowned, "It was a bit of a stupid thing to do don't you think?" In someways he found the notion of the Twins rebelling like this to be absolutely hilarious but he was their older brother, he was supposed to look out for them and he knew that in the long run they were only hurting themselves so he had to discourage them from doing it again.

"You know he has office hours too don't you? Where he is actually obliged to sit and talk to any students that call into him. Getting yourselves detention isn't actually any guarantee of being able to talk to him. He could assign you to Filch, and even if he doesn't there is a good chance that he will also have other students there.

"Speaking like someone with experience" Lily quipped, as she slipped out of his embrace and moved closer to her twin.

Harry blushed, he had deliberately acted up in their fathers class to try and get his attention before too so he was being very hypocritical right now and the Twins knew it.

"Trust me, speaking as someone with experience there are better ways to go about this."

The Twins shrugged and changing the subject asked how his day had gone.

"It was fine, nothing too wild or exciting." Harry replied. "We had Father for Defence against the Dark Arts though which was kind of strange. I don't know where Lupin was, he wouldn't say."

He was interested to learn that Lupin hadn't taken the twins class today either, they had had professor Sinistra. It wasn't particularly unusual for teachers to be unavailable from time to time though so they didn't think too mush of it and before they could start to discuss anything else some of their friends appeared and came over to join them, excitedly saying hello to Harry and asking if the Twins were going to dinner with them.

Harry waved them off "Good luck with Detention"

It wasn't actually a detention. He would make them rebrew the healing potion and then lecture them on their stupidity until he went hoarse but he couldn't bring himself to be the one to tarnish their otherwise gleaming records, even if a detention would have been well deserved. Plus he couldn't be dealing with the ribbing it would earn him from his colleagues.

The Twins arrived on time, looking suitable morose, and went to take a seat at the same bench they had been sitting at earlier.

He looked at them. "I don't think so." he said, shaking his head as he moved one of the stools round to the side of the bench and gestured for Lily to sit.

He then did the same at a bench on the other side of the room for Evan, leaving them sitting with their backs to one another.

"I thought we were brewing the potion again?" Lily asked in confusion.

"You are, but I don't want any talking this time."

"But how are we meant to brew a potion together like this?"

"You aren't brewing the potion together." he told her, "I want two potions."

"But that's not fair, everyone else got to do it in pairs." His son argued.

"Was your behaviour today fair?" he asked before telling them that the other students got to work in pairs due to the time constraints of the lesson whereas they had all night, "And unless you want to be here for the entire night, I suggest you get started."

"You can't keep us here all night!"

"Trust me Mr Snape, I can and I will." He warned before sitting down and turning his attention to his marking, clearly signifying that they were done talking.

"Aren't you going to tell us off again first?" Lily asked sadly.

He looked up, "We will discuss your deplorable behaviour when you are finished brewing" he said, tapping at the instructions on the blackboard and gesturing once again for them to begin.

Looking rather defeated the Twins got down to work. It had been a slight stroke of genius having them sit back to back, as it removed all distractions leaving them nothing to focus on except their work so they were making good progress.

They did look up from time to time to glower at him of course but he was plenty used to that so took not heed. It was remarkable to watch how in unison they were, even when parted though.

He hadn't noticed at first, they had obviously started off together and he would have been expecting them to work at roughly the same pace but after a while it struck him that they were actually operating in near perfect synchronicity.

This wasn't unusual per se, they often mirrored each other, but usually once they noticed they started laughing and then it stopped.

He began studying them more attentively. Was this another intriguing facet of their twinship or were they doing it intentionally in some attempt to mock his punishment.

They couldn't see each other but it was otherwise silent down here so they could certainly hear one another, especially when it came to tasks like chopping.

After watching them for a few minutes though he could see that it was definitely unintentional and that they were completely unaware that they were doing it. Suppressing a smile, he made a mental note to test them on it properly sometime and then turned his attention back to his marking.

A few minutes later he was interrupted. "Father?" Lily called to attract his attention.

"Professor Snape in the classroom please." He reminded as he looked up.

She frowned and put her head down.

He sighed, had she wanted to ask something about the work or was it something else? Rising from his seat he went over to her. "What is it Lily?" he asked softly.

She scowled at him, "Miss Snape in the classroom no?"

She looked so cross that he almost laughed, but thankfully he managed to suppress it, she had been in the process of carefully weighing out her silver flakes and he certainly didn't want to prompt a repeat of this mornings incident.

Crouching down beside her, he tenderly brushed some stray hairs, damp from the steam of the cauldron, back from her face, and asked again what she had wanted to ask him.

She leaned into his touch, "Why is it that a little bit of silver is necessary for the potion but too much ruins it? And how did someone work out what the right amount was?"

He smiled at her and then addressing his son, asked if he was able to answer his sisters question.

"Silver has antibacterial properties, it's not one of the essential catalysts in the magic part of the potion but it makes it more effective, it's all about ratios though and if you add too much of anything it throws everything else off." The boy reeled off confidently. "Adding too much silver can make a potion particularly volatile because while silver itself is a rather stable element, it has the highest electrical and thermal conductivity of all metals, so it can make the potion become supercharged and then the interactions of the other ingredients start going haywire."

"Very good," he nodded sincerely, "I would be incredibly impressed with your knowledge in this regard had you not put it to such ill use this morning." he told him, making him blush, before answering the second part of Lily's question which was basically a lot of maths and a little bit of trial and error.

He then watched them carefully as they added the necessary amounts of silver to their potions and pointed out the differences in how it reacted now with the correct amount as opposed to this morning before leaving them to finish up.

When they were done, he checked their work, and was pleased to confirm that both potions were flawless. He then had them bottle them up for use in the hospital wing and when they had finished tidying up he went to sit down with them, turning them around to face him.

He told them that he was incredibly disappointed with the way they had behaved that morning both on a health and safety and on a personal level and made them promise that there would be no further repeats of it. He then advised Evan that he would be docking his pocket money until he had recovered the cost of replacing the silver flakes he had wasted. "Technically Lily you were not the one who sabotaged the potion, so I will not include you in this part of the punishment, but you knew what he was planning and while you didn't really encourage him you didn't stop him so it's up to you whether or not you share yours with him in the interim."

Lily looked at her brother and nodded, she would share.

Severus then asked if they understood why he had punished them before confessing that he wasn't going to record it as a detention on this occasion but that if they ever did anything like it again he would not be so lenient. Finally he asked if he could have a hug.

Both children launched themselves at him, nearly toppling him off his stool. He held them tight, and kissed the tops of their heads, feeling the stress of the day start to slip away.

They stayed like that for a few minutes, the children clinging desperately to his robes until Evan suddenly realised what he was doing a took a step back. "This is highly inappropriate classroom behaviour, don't you think Professor Snape." he quipped, making them all laugh.

"Could we go to your quarters now?" Lily asked hopefully, still leaning into him.

He looked at his watch, it was after half eight, and shook his head. Aside from not wanting to reward them in any way for their poor behaviour, it was getting late and he had rounds to do. "Maybe next weekend Darling." he told her before stating that he would walk them back to their tower but that then he would have to attend to his usual evening duties.

On his way back down, he met Harry, Weasley and Granger on the third floor landing.

It was very late for them to still be wandering about, although technically not past curfew.

"What are you three up to?" he asked suspiciously.

"Coming back from the Library, Professor." Hermione told him, raising her armful of books as evidence.

He frowned and lifting the book at the top of the stack examined the title. It was a history text, probably just homework then he thought disappointed, he had been half hoping to discover that they were doing further research on werewolves.

Returning the book to see, he looked around and satisfied that there were no other students within earshot turned to his son. "Well come on then, aren't you going to tell me off for punishing the twins?"

Harry looked at him in surprise and shook his head. "Err no I would agree that blowing up a potion warrants a detention."

Weasley began to laugh until he shot him a look that turned it into a cough.

"I hope you said that to them when they told you earlier."

"You were watching us?" Harry questioned, feeling aggrieved.

"School corridors aren't exactly private meeting places." he pointed out before reassuring him that he hadn't been able to hear them.

"I did tell them that it was wrong to try and blow up their potion, but don't you forget about what it is that has them acting out in the firstplace." Harry said haughtily before turning to his friends and telling them to come on, "We have to get back to the tower now, goodnight Professor."

Severus sighed, "Goodnight Mr Potter-Snape,"