Snape did have quite a bit of backbone, it had to be said.
Perhaps unwilling to let Kyle help him a second time, after entering the Room of Requirement this time, he had stayed inside for a full five days without stepping out once.
Everything else was easy enough to deal with. After all, this was a real castle, and it had everything one could need.
The only issue was food... Kyle had no idea how he had managed to last that many days.
Maybe he had Kanna bring food in for him, or perhaps he drank potions.
Like Invigoration Draughts. One bottle could keep someone from needing food for an entire day, but the drawback was that they tasted awful.
Kyle had tried one once. It felt like every disgusting flavor of Bertie Bott's Every Flavour Beans had been mashed together, juiced, and then had a handful of dirt thrown into it.
If Kyle had to choose, he would rather bring extra bread and roast potatoes in the morning than drink that stuff.
But Snape could probably endure it. If he got himself a bag enchanted with the Undetectable Extension Charm, carrying ten or twenty bottles of Invigoration Draught would be no trouble at all.
As for exactly what Snape had done, Kyle had no idea. Apart from exchanging a few words on the first day, the two had not spoken again.
Mostly because there had been no opportunity. After all, the one place Kyle least wanted to go was the Potions classroom.
The next time he saw Snape was on the sixth day. He looked noticeably thinner than before, but his eyes were bright.
It was clear that, like the other professors, Snape had gained a great deal.
Kyle was curious, but he knew Snape would never tell