They walked all the way up until they reached the very top.
Severus looked around. It was bitterly cold here; even fully geared up, he found it rather hard to bear. An old man...
LordVoldemort knew what Severus meant, so he tilted his head and whispered, "There is someone else capable of casting spells without a wand or a sound. Keeping the place warm is easy enough, and he doesn't mind transforming himself, which is why he lives like this."
Chapter 57