Duergars in Barxley

Some background for you

The adventure takes place in a world I created for a D&D campaign in a world named Elhassia, in a region I called Ghüest. This region's landscape is dotted with small villages here and there and four cities, three of them on the coast. Most people here live simple lives, usually not affected by large plots or great threats, not even during the war that ended around 300 years ago. But that is about to change in the road town of Barxley.
I got to say, it's not only my first time writing a one-shot, it's also my first time writing anything that is supposed to be read by others, so I went with something not-so-innovative in the fantasy genre. Also, I wrote this thinking about using D&D, so I don't know how well it could go with other systems, but I don't think it would take much work.
By the way, if someone ever plays this I would like to hear about how it went.

About Barxley and Ijun's route

Ijun's Route, a trail followed by pilgrims and other travelers that is said to follow the steps of Ijun, the god of travelers, after attaining godhood. The road starts at Eleyford, a city found at the heart of the region and goes west, ending at Ijun's cathedral, a great tavern blessed by the god and taken care of by its followers. Barxley is found more or less halfway throgh the route.
The town has around a 100 inhabitants, most of them humans and halflings. Most of them leave from trade and the land and the market, being asparagus their star crop and ingredient, which attracts some food connoisseurs. A few taverns also sustain some families.
The town has recently chosen a new mayor is the halfling Liek Hornpipe. Worried that the citizens are becoming old, he has been trying to attract new people to town by selling terrain at low prices.

Hooks

A few weeks ago the town of Barxley suffered an attack by a group of duergars who kidnapped men and women of all ages. All but one were saved. Just the thay before the start of the adventure an explosion aapeared to occur in the cave where the villagers were found. Further investigation in the cave led to the discovery a hidden entrance to an unknown location.
The classic hiring of adventurers to investigate can work as well as always but I like better the idea of the characters being part of the community or the neighboring towns, taking arms to protect their loved ones and/or their neighbours. The town is well liked by the travelers of the route so maybe a few adventurers currently passing through or resting in Ijun's cathedral could have taken upon themselves to investigate and help the town.
Maybe more kidnaps have happened in other towns in the wait of help and with how little duergars are seen on the surface is likely that more and more people are going to become interested in the cave and ask themselves about ther agenda.

Let's start this

1. Barxley

Whether the party starts in Barxley or not they should go talk to Liek Hornpipe before leaving for the cave.

It's early in the morning, the sun just starting to shine. Some people are preparing the market in the town square and a few caravans are already leaving. You and your group are prepared too, as you decided to explore the secret passage that was recently found in the cave. Liek Hornpipe, the town mayor told you to meet him here and tell you everything he knows.

Liek Hornpipe

Liek is a a 30-to-40 year-old halfling. He has short hair, a well kept goatee and mustache and wears simple linen clothes. He tries to look cheerful and optimist but those who know him can tell that the situation has him deeply troubled. He answers truthfully to any questions asked.
As for the information he posseses:

• He will tell the party where the cave is found and how to reach it. He can offer a guide if needed.
• If asked about the missing person he will tell the party she is a ten year-old girl, daughter of the owners of one of the town's taverns.
• If asked about money he promises each character 50 gold coins. If pushed for more he offers unlimited free meals in the town's taverns with a smile. He may be pushed or persuaded to add a 100 extra gold coins from his own money. Another option would be to offer some land or other property.

2. The cave

2a. Entrance

After a half an hour trek north is found the cave were the passage was found. The cave entrance is not hidden in any way. The inside of the cave is big, with a few cells carved in the walls were the villagers were kept when kidnapped. The cave is full of debris and marks of burning in its walls. It shouldn't be too hard to find the passage.

2b. The path below

As you advance down through the passage and the light from the entrance stops giving you light you start to notice the temperature rising and more marks of fire in the rock walls.
At the end of the passage you find yourselves in front of a metal door with a combination lock. No sound appears to come from the other side.

Both the door and the lock are made of adamantium, breaking it should not be easy. No sound can go through either side of the door. Near the door the charactes can find a piece of burnt parchment that reads:

"Just in case you moron forget: The first becomes smaller if you turn it upside down, the third is the first upside down and the second is nothing compared to those two."

The lock combination is "906".

3. A chaotic project

In the room at the end of the cave the group can find the kidnapped girl behind a metal door in the wall. In the room with her are a duergar and a deep gnome. The duergar is bald and has a great white beard but looks like it has been recently burned in some parts and the gnome has singed long hair and no eyebrows. Both have a dark-ish grey skin tone, are wearing simple robes that act as lab coats and look as if they haven't slept in a few days.
As the characters appear in the room the duergar looks visibly angry and tries to threat the party away while the gnome tries to explain what's happening here. If the gnome is given the chance to explain himself the duergar does a strange movement under his robes which opens the door to the cell in which the girl is found, shuts the entrance to this room and tries to escape through a secret trapdoor that shuts behind him. If somehow stopped he will attack the characters until left.
If the characters reach behind the trapdoor they find a giant spider with a saddle attached to a wall with a chain and an unlocked chain by its side. The duergar took the other one and fled through the maze like caverns. Up to two human sized characters could try to ride the spider and chase after the duergar.

3a. The dragon girl

The girl comes out dissoriented from the cage and as she sees the party and the gnome the temperature of the room starts to raise and she starts to attack anyone that she can see. She looks human, but she has grown horns, tail and other draconic features. When combat starts the gnome begs the party to not kill the girl and starts working on a way to open the door the duergar closed.
You should make clear that the temperature is quickly raising, making it dangerous to fight for long, and even with fire resistance the fire attacks of the girl will end up consuming the air of the room in the long run. The party could either knock down the girl or help the gnome open the door. If they escape the room they can trap the girl inside and she will eventually fall unconscious due to the low levels of oxygen.
After waking up she will be exahusted, incapable of attacking the party. If talked to and explained the situation she cries and acepts returning with the characters.

3b. Much needed explanations

After the conflict, if alive, the gnome presents herself as Issilda Smelter and is willing to answer the party's questions. If the duergar is alive, it refuses to answer any questions, unless forced or persuaded in some way. I assume the characters ask the gnome

• If asked about what her purpose was she explains that they were trying to artificialy create a sorcerer, using alchemical concoctions from unhatched dragon eggs.
• If asked about the reasons she tries to explain that the underground dwellers have recently been attacked by entities from other planes. As the casualties grew, a cooperation agreement between duergars, drwos and deep gnomes was signed. This investigation was part of that agreement.
• If asked about her partner she reveals that his name is/was Ragnar Ironspite. She didn't know much about him, but despised the way he treated the girl.
• The gnome shows genuine regret for what she has done, but explains that she had to think first about her people and family. If asked to come with the group to pay for her crimes or in a more friendly way, she accepts.
• If asked about why they chose the girl she explains that the girl proved to have a greater than normal resistance and constitution, even for her age, so the odds of her surviving were higher.