From the introduction:
It is said amongst the free citizens of Arborell that the Brethren are no more than criminals, men of dubious character forced into a vocation no more respectable than the prison terms they would otherwise have served. The truth is that the Brethren are indeed criminals but their training in the Guild changes them, giving them purpose and the skills necessary to survive their new vocation. One such man of the Guild was Alrig Damphousse, a career criminal in his youth but a legend of the Deep Guild remembered long after his death. Ambushed upon a mountain trail by a crue of Hresh warriors, Alrig lost an artefact long sought for and hard won. Another Brother might have thanked the Fates for their survival and made for the nearest settlement. Not Alrig. In the depths of a mountain winter he resolved instead to hunt down the crue and get back what had been taken from him. On the trail of the Hresh he followed them into the mountains of Laman'thel and thence to a plateau of fractured ground known as The Steps. There the Hordim made camp and there Alrig made his plans to recover what he considered his property. This is also your mission. Start at the grid square numbered 1 and find a way to get into the camp unseen and steal back what has been taken from you.