After a brutal war, the Empire of Zol reigns supreme over rival Aquafa, with the exception of the Fire Horse Territory where feral dogs that once carried the deadly Black Wolf Fever roam freely. During a dog attack on a Zol-controlled mine, Van, a former enslaved soldier, and a young girl called Yuna are bitten but manage to survive. Now liberated, they aim to live a tranquil life in the countryside. However, when the fatal virus resurfaces, they find themselves caught in the midst of a conflict that transcends individual borders.