[It is time.
The chill which had come from the now-open, unnumbered room has now begun to seep into the rest of the Depths. It seems to call to the Titled, beckoning them to come forward and to face whatever is now beyond that door.
Fie and Rubedo were right - that room was, indeed, the exit to the Depths. And at the end of the staircase is a door, which the Skeleton Key can very easily open. A few seconds later, the door at the top of the stairs opens.
And the city within the cave below is revealed to them, as they stand on a platform high above the ground.
The ruin still looks as new as it did the day it was built. The air here is cold mountain air, though the only light seems to come from one massive building carved into the very rock of the cave. There is nothing coming from the mouth of the cave save for snow.
On the door they just came through is a single parchment of paper which reads "LEINALZIND OUTER DISTRICT." Each building, they will find, is labelled similarly. Which means there is only one conclusion.
Welcome to the city of Leinalzind, Titled. And good luck, teams.
You will need it.]