King Nikolai Lantsov of Ravka is struggling to rule his country in the aftermath of a brutal war. With allies on the verge of war and enemies ready to attack, Nikolai embarks on a trip to the Tula Valley to get rid of a demon inside of himself, while Nina Zenik works to save the Grisha from imprisonment and death in Fjerda. Along the way, Nikolai and his companions confront unexpected challenges and powerful enemies. 

This story is filled with adventure and explores topics such as love, loyalty, and politics in the world of the Grishaverse. This book can be read on its own but readers can gain a better understanding if they read the other books in the Grishaverse series, the first of which is Shadow and Bone. I think fans of Leigh Bardugo’s work might enjoy this book since it has her intriguing and well written storytelling style.