I've only done a bit of exploring, but it is a little strange, isn't it? They haven't spared anything to make the Tower a world of its own.

[Flooded floor is flooded. He stops a little ways above the last step onto it, peering down curiously. There are probably shadows of monsters beneath the water, how cheerful.]

It's like saying, 'You'll be here for a while, but at least you won't lack for anything.' Not even weather.