Showing Black Arrow by I.J. Parker

Newly-appointed governor Sugawara Akitada and his young, pregnant wife are sent to the snow country in the far north, where no imperial official has managed to survive the climate or the murderous hostilities of the population. As he tries to establish his weak authority, several brutal murders happen and cause an uprising that threatens his life and the lives of his wife and faithful retainers. But worse is yet to come: An old murder has spawned new ones, and suddenly Akitada is faced with doing battle against the army of a treacherous local warlord.