Mother of Flies, an adventure by Greg A. Vaughan with support articles by Kevin Carter, Adam Daigle, James Jacobs, Tim Nightengale, Sean K Reynolds, and F. Wesley Schneider and fiction by Dave Gross, is the fifth chapter of the Council of Thieves adventure path and was released on February 10, 2010.

“ Leaderless and disorganized, the city of Westcrown reels after a terrifying incursion from the infernal realm. Yet while fiends stalked the streets, a more insidious rebellion unfolded below. Now a new power rises to lay claim to all of Westcrown ! Only the insight of a crazed witch might aid the PCs in curtailing this dastardly coup. But can they hope to stand against the true masters of a city poised on the brink of ruin ?
This volume of Pathfinder Adventure Path continues the Council of Thieves Adventure Path, and includes :

"Mother of Flies," a Pathfinder RPG adventure for 9th-level characters, by Greg A. Vaughan
A soul-staining glimpse into the infernal faith of Asmodeus, the Archfiend, by Sean K Reynolds
An investigation of the methods and organization of thieves’ guilds, by Kevin Carter
Varian and Radovan uncover a diabolical plot in the Pathfinder’s Journal, by Dave Gross
Six new monsters, by Adam Daigle, James Jacobs, Tim Nightengale, and F. Wesley Schneider