From the PDF introduction
A Short Adventure for Four 11th-Level Player Characters Featuring Material from Lords of Madness: The Book of Aberrations
Lords of Madness details the D&D game’s most unusual and unsettling creatures-the aberrations. The book also offers invaluable tips for overcoming these creatures, as well as new feats, spells, and equipment based on their abilities. In addition, several organizations dedicated to the eradication of aberrations are presented.
The Flow of Fresh Brains is a short D&D adventure for four 11th-level player characters (PCs). The scenario is not setting-specific; you can place it in any populated section of your campaign world that is a near a medium or large city. The action begins along one of the major trading routes between cities, then progresses to an illithid nautiloid. As always, feel free to adapt the material presented here as you see fit to make it work with your campaign.
This adventure uses the horrific adventure guidelines presented on page 13 of Lords of Madness. Since the encounter levels (ELs) of several encounters are higher than normal for the character level of the PCs, character death is a very real possibility. At the very least, the PCs will find themselves severely taxed during this adventure, so be sure to provide ample opportunities for healing.