Smokestorm Siege

From publisher blurb:

War! The armies of the Drakkari Ascendancy – a vast dragon-ruled empire – scour the lands, carving their way with fire and steel. They encircle and isolate cities while burning surrounding villages, as though trying to root out some mysterious corruption. So far, their advance has been unstoppable. But the winds of war are shifting, and a small band of adventurers are nearing the city of Riversend with a most precious cargo. To keep it safe, they will have to defend the walls of Riversend and survive the Smokestorm Siege…