"Faster Monkey's tribute to a classic dungeon crawl gives you tons of old-school goodness -- rooms and tunnels, wandering monsters, traps and treasures -- in a fast-playing modern form. "The Hidden Serpent" pits low-level Labyrinth Lord™ characters against a secret complex full of varied foes, some working together and some at odds. More than other Faster Monkey products, this dungeon emulates the humor and zaniness of modules from the hobby's golden age, hitting the party with plenty of classic risks and rewards."
There a ton of hidden gems of the OSR scattered about & one of these is Faster Monkey's The Hidden Serpent By Jeff Sparks. A pay what you want love letter to B1 In Search of the Unknown by Mike Carr whose monochrome cover appeared in Basic D&D sets. The Hidden Serpent takes up the material in B1 & expands upon it love letter style to the so-called dungeon crawl style, where the primary goal of the players is the exploration of a dangerous labyrinth to battle monsters and obtain treasure.
There are two things happening in The Hidden Serpent that make the module a perfect add into a Sword & Sorcery campaign that takes place in the Wilderlands of High Fantasy. One is the fact that in the original B1 In Search of the Unknown Roghan the Fearless and Zelligar the Unknown are anything but squeaky clean. These are two ruthless bastard adventurers whose exploits in B1 fit the City State of the Invincible Overlord background. The Hidden Serpent expands upon this & adds in all kinds of campaign wrinkles.
Perhaps the 'heroes' Roghan the Fearless and Zelligar the Unknown fell out of favor & they were killed by assassins. The Caverns of Quasqueton has all kinds of possibilities for use with the Wilderlands. And The Hidden Serpent really expands upon this idea of building an entire campaign around B1. And it does it very well. The Zenopus Archives website has an entire section devoted to B1 'In Search of the Unknown'
The Caverns of Quasqueton should be way out in the middle of nowhere but close enough to civilization to have access to the royals of the Wilderlands.
How does any of this relate to Hyperborea?! In a word Barbarians or specifically mercenaries. The Wilderlands is made up of barbarian hordes, tribes, etc. And these were used by the 'heroes' Roghan the Fearless and Zelligar. They didn't plunder the wilderlands but the caravans crossing over from Hyperborea. And so there was a mix of goods & services between the trade crossing between the Nexus gates. This enabled Roghan the Fearless and Zelligar to get rich fast by plundering & doing guard work for the caravans making the crossing.
But all good things come to an end! Or do they?! What is to stop a group or several groups of evil humanoids tribes from taking over the Caverns of Quasqueton?! The Hidden Serpent has several answers within it. If we were relating these adventure events back to Hyperborea then another possibility comes to the campaign fore. Remember that B1 is named after the famous or infamous Robert W. Chambers anthology story collection. Perhaps one of the reasons that Roghan the Fearless and Zelligar met their untimely demise is the fact that the wizard was dallying with 'The King In Yellow'.
Does this dallying with the dark powers of the 'King In Yellow' make the area as not only attractive to the orcs of Hyperborea in the form of the tribe of the yellow hand. But also far worse chaos spawns of the King?! This would be the perfect time to employ Gregorius21778: Beware of the Spirits of the Woods as the tortured spirits of nature that echo around the Caverns of Quasqueton. Nature itself another victim of the evil of Roghan the Fearless and Zelligar. Could the caverns themselves be a twisted Nexus gateway to the 13th or 14th century of Lamentations of the Flame Princess rpg?! The magicks twisting the whole cloth of time like the broken threads of a loom?!
The Hidden Serpent & B1 'In Search of the Unknown' could act as the catalyst for an entire campaign in the back parts of the Wilderlands of High Fantasy. Here away from the prying eyes of the authorities the hills ran wild with the blood shed & weirdness of Roghan the Fearless and Zelligar.