In a world ravaged by ice and snow, civilization is on the brink of collapse thanks to the elusive Ice Witch. Fighting against the cold has brought out the worst in humanity, leading to cults, violence, and the persecution of the Blessed—those born with supernatural powers.

Agni and Luna—blessed orphans with regenerative powers—are making the best of their situation within a small society of elders; their affection for each other serves as a distraction from the uninhabitable climate. Nevertheless, what little serenity they have is stolen away when army commander Doma passes through and incinerates the village they are seeking refuge in—Agni's beloved sister included. Doma's flames do not extinguish until they have reduced their target to ash, and due to Agni's remarkable regeneration, he remains ablaze and in constant, excruciating pain.

After nearly a decade of enduring the pain, Agni has conditioned himself to tolerate Doma's flames. However, his burning vengeance is as fierce as it was on the day Luna was taken from him. As Agni traverses a frozen wasteland, he vows to avenge his sister and kill Doma.