It is 997 CE, the end of the Dark Ages. England is facing attacks from the Welsh in the west and the Vikings in the east. Those in power bend justice according to their will, regardless of ordinary people and often in conflict with the king. Without a clear rule of law, chaos reigns. In these turbulent times, three characters find their lives intertwined.

Brunhild was a foreign princess, raised to be married off for the sake of alliance-building. Her sister-in-law Fredegund started out as a lowly palace slave. And yet - in sixth-century Merovingian France, where women were excluded from noble succession and royal politics was a blood sport - these two iron-willed strategists reigned over vast realms, changing the face of Europe.

It's 1811, and the threat of revolution haunts the upper classes of King George III's England. Then a beautiful young woman is found savagely murdered on the altar steps of an ancient church near Westminster Abbey. A dueling pistol found at the scene and the damning testimony of a witness both point to one man - Sebastian St. Cyr, Viscount Devlin, a brilliant young nobleman shattered by his experience in the Napoleonic Wars.

After losing his leg to a land mine in Afghanistan, Cormoran Strike is barely scraping by as a private investigator. Strike is down to one client, creditors are calling, and after a breakup with his longtime girlfriend, he’s living in his office. Then John Bristow walks through his door with a shocking story: His sister, the legendary supermodel Lula Landry - known to her friends as the Cuckoo - famously fell to her death a few months earlier.

London, September 1666. The Great Fire rages through the city, consuming everything in its path. Even the impregnable cathedral of St. Paul's is engulfed in flames and reduced to ruins. Among the crowds watching its destruction is James Marwood, son of a disgraced printer and reluctant government informer. In the aftermath of the fire, a semi-mummified body is discovered in the ashes of St. Paul's, in a tomb that should have been empty. The man's body has been mutilated, and his thumbs have been tied behind his back.