After the Black Iron Army crushes the northern clans and takes their city, Seren, eldest daughter of fallen commander Eirik, walks alone into the enemy camp with the Frostblade and tries to kill Roderic Vorn. She fails—and is seconds from execution when her younger sister Nyla fires a Frostbow arrow into the heart of ten thousand soldiers. Together, the sisters tear through the encirclement and escape into the mountains, only to be hunted by General Volker and his cavalry. A collapsing ice cliff nearly kills Nyla, old wounds between the sisters explode into the open, and this time they make a choice: no more fighting alone. When they turn on Volker and drive his riders back, word reaches the hidden survivors that Eirik’s daughters have returned—and resistance is possible again.
But one victory becomes a war. Hunters, old soldiers, smiths, riders, and rival clans begin gathering around them, while Roderic unleashes assassins, blackfire, and weapons built to break their frost magic. As Seren and Nyla grow from hunted sisters into the leaders of a rising army, an even greater battle waits beyond the snow: can they reclaim their home before the enemy destroys the people they are trying to save—and what will they have to sacrifice to do it?