She was the first saint of Rus'. But before she was a saint, she was a wife, a widow, and an avenger.

In the middle of the tenth century, a young woman from the northern forests named Olga is married to Igor, the Prince of Kyiv. It is not a fairy-tale romance, but a union of two lonely souls: Igor, a prince haunted by the ghost of a father he never knew and the fear of being seen as weak, and Olga, a girl raised by a shaman grandmother who taught her to remember everything.

When Igor is brutally murdered by the Drevlian tribe-torn in two by bent birch trees as punishment for demanding excessive tribute-the world Olga knows collapses. Left with her young son, Sviatoslav, and a kingdom on the brink of chaos, she faces an impossible choice. The boyars see only a woman; the Drevlians see only a prize, sending envoys to force her into marriage with their own prince, Mal.

But they have made a fatal mistake. They have underestimated the memory of a woman who never forgets.

What follows is a campaign of calculated, terrifying revenge. Olga buries the first party of Drevlian envoys alive in a pit. She burns the second party to death in a bathhouse. She slaughters the third party at a funeral feast for her husband. And finally, she lays siege to the Drevlian capital of Iskorosten, using an ingenious and horrifying tactic-burning the entire city to the ground with the help of birds carrying lit tinder to their own nests.