Surinak Estate

In the year 1239 DR, the Duke of Arcata appointed a lesser-known family, the Surinaks, as protectors and lords of the village of Ostrav north of his capital of Valls. At the time, Ostrav had only about 200 residents. Though most other settlements in Arcata were mining towns and outpost in the Galenas, Ostrav relied on farming.
The Surinaks used their connections to bring prosperity to Ostrav. Soon the town became a major stopping point between the Barony of Bloodstone and the capital of Heliogabalus. The Surinaks also worked with the other settlements of Arcata to funnel the outputs of their mines through Ostrav, often with lucrative contracts. With their newfound wealth, they began construction on their manor house, northwest of Ostrav,
In the year 1252, Baron Lucius Surinak married his son, Marcius married to Sadiri Dioso, an influential family out of Heliogabalus, increasing the power of both noble houses. Marcius was an adventurer and returned from an expedition to the jungles of Chult betrothed to a woman he didn't know, or very much care for. Returning with him was a young boy named Luca, who he introduced as a fallen friend's orphaned son. Shortly after his return, his father's sudden death required that he accept the title of Baron and wed Sadiri despite their mutual dislike.
Soon after their wedding, Luca died from eating a deadly dose of poisonous berries from the baron's garden. The Baron and Baroness became withdrawn and secretive. A wall was erected around the Estate, built by workers brought in from other settlements. At the time, no one questioned that those workers disappeared after the construction was finished.
Soon other servants and wayward children started disappearing, then young vagrants and apprentices from Ostrav itself. Though the Surinaks took care to get rid of the bodies and other evidence, the idea that they were consorting with demons became an open secret among the villagers. On a fateful winter day in 1266 DR, while the baron and baroness were conducting business in town, an angry mob attacked them and other members of House Surinak, and hanged them without a trial. The town then descended into chaos as residents turned on each other, accusing their neighbors of colluding with the hated nobles. Eventually, the crisis waned, but the town paid a high price in blood that it still remembers today. A grim reminder of the past, the town still maintains its gallows in working order, waiting for any sign of the returning Surinaks.
The Surinak Estate lay abandoned for over a century, but recently, a demon named Wormgnash—a vermlek born of the town’s late, wicked gravedigger—decided to settle there, drawn by the place’s isolation and latent sense of suffering.
Along the way to the estate, Wormgnash came across a band of chitines that lived in nearby shallow caves. Seeing the weak-willed creatures’ potential as allies, Wormgnash convinced them that he could give them great power—enough to overthrow the puny humans of Ostrav - if they followed him.
Naturally, the chitines eagerly acquiesced, and once at the estate, Wormgnash transformed them with demon’s bile. Now, the fiendish chitines and their vermin allies guard the demon’s lair until he can enact his final plan: the utter destruction of Ostrav - for while wallowing in his lair and the disgusting demon’s bile that resulted from the merchant’s corpse he currently wears, Wormgnash discovered a way to bring his demonic brethren to the Material Plane.
Coincidentally, though she knows nothing about the vermlek or other creatures lairing there or the plans already in motion, Ostrav’s mayor Sandra Trinelli recently discovered that the Surinaks kept records about their long-ago victims. Hoping to finally grant the victimized families some closure—as well as temper the anti-noble attitudes that are decidedly bad for the town’s business—she has put out a call for outside help to find the documents hidden somewhere at the estate.