You crossed into Essington shortly after the encounter with Coppersmith and Raktooth. Out of the Iron Guard’s jurisdiction, the travel was easy. You had no trouble with bandits or monsters, and arrived two weeks later in Crosley, a backwater regional capital at a river mouth near the Darkspear Chain.
The locals were friendly but did not think it was wise to venture into the mountains. None had heard of Mortimer Greycastle, and none knew of anyone who had returned from the mountains. You didn’t stay long.
According to the Sage of Deancroft, it was a three-day hike from Crosley to Greycastle Redoubt. The mountains were cool and dry, with low scrub but no large forests. Halfway through the journey, you encountered two Zern Blade Thralls, large snakelike creatures with blades for arms, and their master, a Zern shapeshifter. The resulting battle took little time.
Toward the end of the next day you saw your objective. Greycastle Redoubt had not taken the years well. Every tower and wall was falling down. The portcullis was a twisted mass of rust and rotten splinters. The courtyard was full of the decaying, rotting remains of wooden buildings fallen into their own cellars. But in the center of it all was a ten-foot gleaming silver cube.