Pathfinder For the Queen and the Empire is the fourth chapter of the Hell's Vengeance saga.

Her Infernal Majesty Queen Abrogail II of Cheliax summons her agents in the city of Egorian to discuss the challenge posed by the Glorious Claim.

Once they arrive in the bustling capital, the adventurers find themselves embroiled in the Machiavellian politics of the imperial court. To impress the queen and secure an audience with her majesty, the evil characters must scour the City of Spines to uncover and eliminate a secret organization operating to free the enslaved halflings.
But to gain the queen Abrogail's unconditional trust, the adventurers must make a sacrifice for the reigning monarch and renew the pact with the Hell of House Thrune, and many would like to see the sovereign deposed, both within the court and outside it. This volume of Pathfinder Saga continues the Hell's Vengeance Saga and includes:

• “For the Queen and the Empire,” an adventure for Pathfinder RPG suitable for 10th-level characters, by Stephen Radney-MacFarland.
• An atlas of Egorian, the City of Spines and capital of Cheliax, by Dave Gross.
• A look at the abolitionist secret organization known as the Bellflower Network, by Crystal Frasier.
• Four new monsters ready to challenge adventurers, by Garrett Guillotte, Steven T. Helt, Luis Loza, and Stephen Radney-MacFarland.