Supplement for the Nova Roma setting from Avalon games' Heroes Wear Masks for Pathfinder.
Carcer Maximus Innsmouth, more commonly known as Innsmouth Superprison, is the highest concentration of evil in one location in the entire world. Its mere presence throws off tarot readings for miles around. The inmates are as ingenious as they are evil, making mutagens out of cleaning fluids and turning everything they can pry off the walls into makeshift ray-guns. The administration is able to maintain some vestigial semblance of control only by being more evil and insane than the prisoners. This leaves anyone sane caught between a rock and a jagged whirling place.
Innsmouth Superprison is a detailed look at the most notorious prison in the Nova Roma setting. This book contains information on the prison itself, the staff, inmates, and gangs of Innsmouth, as well as the many special security measures (and how to defeat them).