The Crimson Void is one of the most interesting RPG materials I've seen. The Crimson Void is not exactly an adventure; the Campaign Elements (CE...hehe) series is designed as drop-in content to any campaign world. TCV is something that can be weaved into a long-running campaign. It contains a few surprises that only insightful, or persistent, players will be able to dig up.
[5 of 5 Stars!]