Neville Longbottom looked at his first-year class and smiled.

It was their first lesson and, as every year, he amused himself seeing how nervous his students were, how they glanced at him with fear and excitation tainted in their eyes, how they stood quiet every time he opened his mouth.

He looked at Teddy Lupin, who was carefully taking notes.

Of course Neville knew him. He had seen it at Harry's, at the Burrow's, at Weasleys weddings and birthdays.

He looked at him with more attention. He incredibly looked like his mother: he had her heart-shaped face, her thin lips, her Metamorphogus Abilities. But there was something about him, Neville thought, that made him remind of his father. Maybe it was because of that aura of responsibility and seriousness, maybe it was that sober and earnest look in his eyes, maybe it was that ironic and yet sweet smile that sometimes appeared on his face.

Neville glanced at his watch.

'Class is over' he said 'For the next time please read carefully the introduction of your book'

He looked at Teddy, who was packing up his stuff.

'Mr Lupin, could you stop for a minute, please?' he said.

'Yes, sir?' Teddy said getting closer to him.

Neville looked at him and suddenly remembered the last time he had seen his father.

It was the day of the Battle of Hogwarts and he was in the Room of Requirement.

'Professor Lupin!' he had said as he had caught glance of his former teacher.

'Hello Neville' Lupin had answered smiling kindly 'I haven't seen you for ages'

'Yes, right... erm... I'm sorry that when you quit I didn't... you know...'

'Don't worry for that, Neville' Remus said with a sympathetic nod.

'No, the thing is that... I wanted to tell you... that...'

But in that moment Kingsley had called Remus and Neville had never finished his sentence, had never said what he wanted to.

There's plenty of time he had thought I'll see him again after the Battle. When all this will be over.

But, as he would have sadly found out, there wouldn't have been other chances to talk.

And now Neville was there, looking at Lupin's son.

There were lots of things he wanted to say.

He wanted to say that he was grateful to Lupin for having given him confidence, for having assured him that he was going to be a good wizard.

He wanted to say that without Lupin he would have never found the strength to struggle against the Death Eaters, to fight for his values.

He wanted to say that his biggest regret was that he had never told him 'thanks', that if he had a Time-Turner he would come back to that night, to the night of the Battle of Hogwarts, just to tell him that.

He wanted to say that he had become a teacher mostly because he wanted to follow Lupin's path, to keep helping students just like Lupin had done with him.

He wanted to say that he was honored and even a bit afraid of having Teddy, Lupin's son, as his student.

He wanted to say that that night, during the Battle, he would have never told Voldemort those words, he would have never killed Nagini if he hadn't seen a couple of minutes before Lupin's body laying on the ground.

He wanted to say that after the Battle he had looked for Dolohov's body, as he knew he had been killed. You have killed my teacher, he had whispered, rage and sadness tainted in his voice.

He wanted to say so many things, too many things, he though as he looked at Teddy Lupin's puzzled face.

'Teddy...' he said slowly.

'Yes?' the boy asked, glancing nervously at him.

'You know your father was my teacher, don't you?'

The boy nodded.

'Well... I... erm...' now or never, he thought'thank you' he finally stammered.

Teddy looked at him, wearing a puzzled expression.

'Erm... you're welcome' he said with a kind smile.

'Well, that's all... see you next lesson then' Neville said quickly.

'Yes. Good afternoon' Teddy said.

Neville nodded, smiling. Even though Lupin had been dead for more than ten years, even though he was a grown-up man now who had learnt to deal with his grief and his regrets, he felt incredibly and unreasonably happy that in some way he had finally found a way to show Professor Lupin his gratitude.

'Professor Lupin!'

'Hello Neville. I haven't seen you for ages'

'Yes, right... erm... I'm sorry that when you quit I didn't... you know...'

'Don't worry for that, Neville'

'No, the thing is that... I wanted to tell you... that... thank you'

'You're welcome'

A/N What did you think?

I had this in my mind for long time but I never managed to write it, mainly because it is linked in some way to a personal experience of mine... Anyway, reviews will be appreciated!!