Deep in the frozen north, facing the northern sea lies Corpsehaven a city built into a sheer cliff, a walled city that extends to the sea. This city is a silent place, filled with the dead and those that would consort with such creatures.
The PCs are setting up camp at the end of their first day of walking through the Esh-Inel Mountains, when they hear in the distance a low rumbling, like thunder. It grows progressively louder until it echoes off the mountainous bowls around them, then dies away again. At its worst the ground starts trembling. It happens every day at this time, and it is the noise of the Great Carts on the dwarfish underways returning home after a day mining, laden with many tons of ore.