The Army of the Regent Arosh advances on the forces loyal to Saalshen, homeland of the serrin people, as the serrin's friends are in full retreat. Their only hope is to reach the city of Jahnd – the serrin word for Haven – across the River Ipshaal, the only human city in Saalshen itself. The Army of Lenayin marches with the Regent, but Sasha, sister of the newly crowned King Koenyg, can no longer stomach the awful cause for which her people march.
As tensions between herself and her brothers rise, Sasha's sister Sofy, wedded to the Regent, travels to the city of Tracato, to attempt to negotiate a peaceful transition of its wonderful heritage of her husband's rule. But there are forces beneath the Regent's banner that wish to see all serrin and serrin-influenced civilisation destroyed for good. As the serrin people fight for survival, families must be betrayed, enemies reconciled, nations persuaded and great armies fought, as A Trial of Blood and Steel reaches its dramatic conclusion.