This is a short adventure for a party of four level 5 characters.
It’s a well known fact that the night is dark and full of terrors. In certain places in the world, confrontations with the dark are inevitable and come about with alarming regularity. The further North your adventurers travel, the closer they come to being shrouded in perpetual night as the winter sun creeps closer and closer to the horizon, until eventually it sets for days or weeks at a time.
While many might consider such a dark, cold and dismal place to be the last part of the world any sane living person would want to eke out an existence, for the Druids of Memory that perpetual night is a sacred time. A time when the ghostly lights of the aurora light up the night sky, stars shine freely, and the dreams of the cosmos can share their secret with the living. The Druids of Memory are the ancient protectors of a grove of massive crystals that grow in a snowy tundra valley. Over millions of years, the crystals have grown, fed by the long exposure to the magical aurora above, able to capture the memories of the cosmos.
The Memory Crystals are magical artifacts that allow glimpses of past eons to those that attune to and focus on the crystal’s power. To do so is a ritual version of the spell Commune that allows the caster to communicate with the memory of the cosmos. The caster can ask questions about the history of the universe, world, or its inhabitant cultures. The crystals do not possess information respecting individuals, so questions about a historical figure will not glean information unless phrased in a manner that references the shifting of whole cultures and civilizations.
As you might imagine, such knowledge is both highly valuable and highly dangerous. Knowledge of technologies and magics that shaped or destroyed past civilizations could wreak havoc if allowed into the wrong hands. Fortunately, the Druids jealously guard the knowledge of the crystals, forbidding their use by outsiders and maintaining the secrecy of their existence with a network of dedicated acolytes that seek out and destroy references to the Grove of Memory.
The Enemy at the Gates
Despite the best efforts of the Druids, word has gotten out about the Grove. Perhaps an agent had defected, thinking the Memories of the Crystals could serve a greater good, perhaps they were captured and tortured to giving up their secrets. Either way, knowledge of the Crystal Grove and the potential power it contains has fallen into the hands of the evil Clan Grikskar.
Clan Grikskar are a powerful and ambitious group of Duergar families. They have long scorned being forced to survive under the foot of the Drow and other subterranean horrors. Led by the powerful dark mage Humulos Grikskar, the clan has discovered the location of the Grove of Memory and now seek to unlock its ancient knowledge. With the knowledge and technologies of forgotten civilizations, they might establish a new world order in which the dark dwarves are the top dogs.
Clan Grikskar are not a collection of fools. They know that the grove will be well guarded and so they plan to initiate their attack when their own weaknesses will be best neutralized. By making their move during the Winter Solstice, the extended darkness allows the dark dwarves to move, fight and harvest the crystals while the dangers of the sun are well out of mind.
The Attack Plan
The Grikskar clan has a number of skilled artificers and engineers at their disposal, and have been preparing for this attack for quite a while. The attack plan is genius, foolproof and cannot fail. Or it wouldn’t if it wasn’t for the fools running the drill. Literally, they’re running a giant drill.
As your adventurers rest, quest or roleplay among the secretive Druids of Memory for their own reasons, a sudden intense grinding and crashing sound can be heard off in the distance. The duergar, piloting a gigantic Drill-Tank, have dug their way from their subterranean tunnels up to the surface. Unfortunately for the duergar, they have missed their target by about a mile. This is close enough for the Grikskar, upon surfacing, to realize their mistake and begin making new calculations. It should also be enough time for the Druids and the adventurers to make preparations for the upcoming siege.
While the Druids, curious about the strange sounds coming from the tundra, send the adventurers out to investigate, the duergar set about clearing rubble and reversing their great siege engine back into the tunnel. Humulos, furious but still cautious, sends a troop of six duergar armed with crossbows forward across the land to scout and report back on the state of the grove. The troop captain has a magical +1 crossbow and four potions of healing. By the time the adventurers encounter the duergar scouts and find the collapsed tunnel made by the Drill Tank, Humulos is well on his way to the Grove again, this time with better aim.
Stopping the Tank
The Drill-Tank presents more than simply a threat of invasion. Very likely the vibrations from its digging and the cutting edge of the drill itself could do lasting harm to the integrity of the crystals. The Druids beseech the adventurers to intercept the tank and stop it before it gets too close to the grove.
Fortunately, the drill-tank is slow, and the druids are willing to help with what power they possess, helping the adventurers to reopen the collapsed tunnel or find another way into the tunnel the tank is digging. The tunnel is large, 15 feet in diameter, with large gridded tracks in the floor where the tank has rumbled past.
Giving pursuit, the adventurers first encounter a troop of six duergar laborers clearing the path of retreat for the tank. They are currently working far enough away from the tank that they are unable to call for backup.
The Drill-Tank itself is a large, metal clad contraption powered by the energy released from the combination of two trapped elementals. It has two panel doors allowing access to the interior, one on the top, and one on the rear. When the players first encounter the tank it is digging along at a steady 10 feet per round pace. The exterior of the tank is crawling with small fey creatures conscripted to maintain and repair the machine as it does its work. An angry crowd of six assembler gremlins accompanied by three duergar guards attempt to fend off the adventurers from boarding the machine. As the adventurers deal with these creatures, veins of crystal in the walls of the tunnel chime, crumble and glitter along with the vibrations of the tank. It should become apparent that the tank is getting close, and time is running short.
If you want to put pressure on the adventurers, start timing their progress. They have just 2 minutes (twelve rounds) to stop the machine after dealing with the last assembler gremlin before the drill begins to do irreparable damage to the roots of the crystal grove.
The interior of the tank has two compartments: an engine room and a pilot’s cabin. Entering through the rear access panel enters into the engine room, while the roof panel enters the cabin. The tank is so loud that anyone inside automatically fails any checks to hear activity outside the tank, and has disadvantage to hear anything happening in the other compartment within the tank.
The engine room contains two assembler gremlins, working frantically to maintain the inner workings of the tank. Two cylindrical cast iron vats, one on each side of the cramped compartment leave just enough room for three medium creatures to stand in single file. Each cylinder contains an elemental – one fire elemental, and one water elemental – and are connected by a dizzying mishmash of metal pipes that feed heat from one cylinder to boil the water from the other and create enough steam to drive the massive machine’s drill and treads. Freeing either elemental would stop the machine and can be achieved by forcing a gremlin to disassemble a containment cylinder or by breaking through a cylinder wall. However, the adventurer’s would then have a very angry elemental on their hands. It takes 6 rounds from an elemental being freed before Humulos realizes something is wrong and checks the rear compartment.
The tank can also be stopped if the adventurers force their way straight through to Humulos in the pilot’s cabin, but given the cramped quarters within the tank, it may be inadvisable if only because he has lightning bolt prepared. Either way, the tank stopping before reaching his goal drives Humulos into an angry rage and he bursts through the back compartment of the tank to get his hands on whoever has foiled his plans. Humulos fights and casts spells viciously, casting dominate on any animals the party may have with them before attempting to kill anyone with religious iconography. When Humulos drops below 20 hitpoints, he will attempt to escape by casting gaseous form. If he has reason to believe that won’t work, or if he is below 5 hitpoints and an elemental is still captured within the tank, he instead casts shatter on the containment cylinders, releasing the furious elemental trapped inside, shouting “If the Great Humulos doesn’t win, no one does!”
Assuming the adventurer’s survive and Humulos is defeated, the Grove is safe and the Druids are happy to reward the players with access to the crystals to each conduct the Commune ritual. However, if Humulos has escaped, it probably will not be long before he returns with some new contraption to attempt to gain access to the Grove.
What’s that? Pathfinder?
If you’ve been hearing Shaun on the Discord or in the ToA Director’s Commentary episodes, then you know he’s been playing Pathfinder 2nd Edition. Here are the stat blocks for Assembler Gremlins and Humulos Grikskar in Pathfinder-ese, if you want to give it a try with this one shot. (Make sure to rebalance the encounters so as not to overwhelm your players with a Severe encounter by accident). The duergar scouts can be duergar sharpshooters from the Pathfinder 2E Bestiary (and it might be fun to throw in a Bombardier).