Alina Starkov, a girl who possesses the power to summon light, is confined underground by a religious leader of her country Ravka after she is weakened by a battle with her nemesis the Darkling. (The battle takes place in the previous book of the series, Siege and Storm.) In contrast to the first-person narration of the rest of the chapters, the prologue and epilogue use a third-person point of view to narrate Alina’s story. Led by a religious leader known as the Apparat, many of the oppressed people in Ravka revere Alina as a saint and are willing to create an army to challenge the military forces of their country. The Apparat has imprisoned Alina underground to try and control her, and Alina has discovered that she cannot summon light anymore, making her weak and frail. However, eventually Alina learns to use the weakness to disguise her growing strength as she recovers from confronting the Darkling.

Alina “performs” her light summoning in front of a crowd of worshipers at a service led by the Apparat. Due to her weakened state, the performance is a ruse created by other Grisha who help Alina appear to summon.