The incredible adventure begun in The Bear and the Nightingale continues as brave Vasya, now a young woman, is forced to choose between marriage or life in a convent and instead flees her home - but soon finds herself called upon to help defend the city of Moscow when it comes under siege. Reports have reached the Grand Prince of Moscow that his countryside is plagued by bandits who appear out of nowhere to burn the villages and kidnap its daughters. Determined to catch the men no one has been able to track, he sets out with his trusted friend, Sasha, a priest with a warrior's training.
The party travels for many days but is unable to find a trace of the raiders, until they come across a young boy riding alone on a magnificent horse who claims he has seen them and can find the trail. Sasha is shocked to recognise the boy as his younger sister, thought to be dead or a witch by her village and riding in disguise. But when Vasya proves herself in battle, riding with remarkable skill and inexplicable power, Sasha realises he must keep her secret as she may be the only way to save the city from threats both human and fantastical.