This adventure module is reminiscent in both title and story of an early Dungeons & Dragons module, In Search of the Unknown. Like his previous module, Metzger lays out this adventure as a collection of resources for setting up the adventure and allowing the players to set their own pace. The environment in town is charged and ready for conflict with plenty of NPCs, and the dungeon itself is large and features a broad variety of challenges. However, unlike the previous one I reviewed it is only meant to be used with Dungeon World rules, though it would not be difficult to convert it to Labyrinth Lord. This is another first in a trilogy which are given traditional module code numbers, Lair of the Unknown is given the code DW1 which probably stands for Dungeon World. I own the original D&D adventure that Johnstone Metzger is name-dropping and I will try to both avoid making direct comparisons or pointing out obvious similarities.
Lair of the Unknown is set up as an introductory adventure for a beginning group of characters, and the first 18 pages could have been a very useful resource all by itself for creating a campaign and pushing the PCs into the direction of adventure. The next parts of the book describe some of the challenges that could crop up both in town and in the nearby dungeon, and these are structured as individual pieces that can easily be dropped into the story or left out entirely. The sandbox nature of the town of Westham puts a burden onto the players to find their own way, but there are plenty of obnoxious NPCs that could make trouble in the PCs lives if they stay in town for too long.
The second half of the book is dedicated to the lair, named Xallevyrx, and it is filled with numerous dangers and threats that would be unique challenges even for seasoned adventurers to overcome. However, the layout of the maps is disorienting and only by reading room descriptions can you understand where they link up, preparation is definitely required to familiarize one's self with the dungeon since several areas of Xallevyrx lead directly to an underground cave system which could act as an alternate entrance or escape route, but the maps themselves are of no help whatsoever. This may be the only thing I found confusing and really didn't like about the module.
The final section of the book details some custom rules and compendium classes to introduce to your campaign, one of which is a full-fledged class dedicated to exploring underground lairs: the Dungeoneer! When I first purchased the module this class was the first thing I read and I made my own custom character sheet for it, though you can also find the details for it, and a series of other classes Johnstone Metzger has written, in a pay-what-you-want collection on DriveThruRPG.
The book really shines in the early chapters, where it is filled with excellent advice and interesting details, but there's a section titled 'They Who Make Trouble' which seems tacked on to the adventure to make it more than just a dungeon. The dungeon itself feels a bit dry and flat, even when I try to ignore the obvious inspirations for it. The most interesting part of the adventure is in the deepest and darkest part of the dungeon, which it is noted that even the author's players never managed to explore. The new Dungeoneer class is also a real piece of quality work and I really like it, but it may seem overwhelming to a beginning player, and it is probably only going to be useful if your campaign focuses solely on exploring dungeons and caves.
You can purchase both pdf and print versions of "DW1 - Lair of the Unknown" at DriveThruRPG or just a print version at Lulu