Captain Will Laurence and his dragon Temeraire must navigate a devastating plague threatening the British Aerial Corps while seeking a cure in the heart of Africa. As the mysterious dragon-sickness ravages the ranks, Laurence and Temeraire embark on a desperate expedition to the African interior, where they encounter unfamiliar cultures and complex political landscapes. They face the dual pressure of military duty and the moral weight of their bond, all while operating under the strict, often rigid, protocols of the Napoleonic-era British military. The narrative follows their progression through a world where the presence of dragons has fundamentally altered the course of global history and colonial expansion.

This installment is widely recognized for expanding the scope of the series beyond the European theater of the Napoleonic Wars. Readers and critics often highlight the author's commitment to exploring the moral complexities of the British Empire's colonial reach through the lens of dragon-human interaction. The narrative is noted for its shift in tone, moving from the structured battles of previous books to a more exploratory and introspective tone as the protagonists encounter new societies. The character development of Temeraire remains a central point of praise, as his perspective continues to challenge Laurence's traditionalist worldview.