Toby wasn't entirely sure what that look meant, but he'd already clocked that there were some mixed feelings purely from the vibes he was getting. Sad vibes, but not altogether distraught. Sad and good. Sadgood. Goodsad. Or something.

"I will," he replied, giving a small and kinda sorta sad but no less genuine smile. Because HE was happy he was leaving, finally graduating, but there were still other feelings that were more difficult to process, that conflicted with the happiness of getting out of here. Because he was leaving people, places, and things, behind. It was a part of life, though, he'd decided. This must have been how Ella had felt when she'd left, and Merlin knew Toby understood what it would be like to stay behind. "And you take care too, sir. Don't go getting caught up in any Hogwarts craziness if you can help it." He left it unsaid, the request that Culloden keep an eye on Soph and look after her and ensure she was happy and safe and everything. Because he knew it didn't need to be said, because Culloden would do that anyway. Same for Kyroh, now he thought of it.

And... wow, he really was leaving a lot behind. Probably... easiest not to think about that for the moment.

"I'll write, too. Keep you updated and all. If that's okay?" Toby had plans to stay in touch with plenty of professors and students, and of course the Potions Master was right at the top of that list.