Understone Pass is the result of a monstrous effort to widen a natural fissure that runs on a dog-leg through the narrowest point of the Blackthorne Mountains. It was undertaken over five hundred years ago by the Baron Council, the forerunner to the Korina Trade Alliance. It takes a galloping horse four hours to go through it.

Thousands of workers and mages made a pass large enough to take a four wheeled cart and opened up trade between east and west. It took fifty years to complete and cost in excess of five hundred lives. And though trade flourished, the pass served to open the rich eastern lands to the hordes of the Wesmen.

Ever since its opening, the pass has been guarded by a garrison stationed in purpose-built Understone Town. Three hundred years ago it was a focal point for the first invasion of Wesmen, backed by the Wytch Lords.

That invasion was eventually repelled and through the intervening years, treaties and rights of passage have come and gone. It seemed with the arrival of Tessaya, Lord of the most influential Wesmen tribe, the Paleon, that a new era of peace and trade was born.

Tessaya though, a shrewd man, recaptured the pass nine years ago, ripping up the old treaties and making new ones that swelled his coffers with levies. He is still in charge today and, with no threat of incursion, the garrison is just seventy five men strong.