"This way," says Elspeth, and she and Jake show them through some more halls, down some stairs, and through a tunnel, then up a spiral ramp to a pleasant little cluster of houses and small nonhouse buildings, with well-cleared paths between them through the snow.

"If the cold bothers you, don't worry - the houses we use for humans have heating," Elspeth assures them. "And there are coats and changes of clothes in a few sizes you can use if you like."