Within a day of entering the Caer Bryr, the villains find themselves standing face to face with Jurak the Eldest, a huge treant. He told them that they had discovered the ancient Horn of Abaddon, which was the treant’s sacred charge. He told them they must turn back. The villains attacked and defeated the treant taking some of the treant’s remains as treasure.
They rested, and made their way into the caverns below. There they discovered some bullywugs (also called boggards, or frog-men). The environment in the covers was wet and swampy and the bullywugs fled deeper into the caves. The villains discovered a pit boiling mud, a pool of acid, and even a large pile of humanoid and animal bones. Finally they arrived in a primitive village surrounded by the bullywugs. One of them declared himself as “Kumanda Slays-Nine-Men”; he was quickly defeated by five men and an ogre (the villains and Grumblejack). Impressed by the villains strength, and persuaded by Captain Atticus Rockhopper, they became the villains minions, with one condition; Zikomo Hears-The-Father, the tribes shaman, was to be put in charge of he bullywugs. The villains agreed, and Zikomo revealed to them, a hidden cavern covered in blue fungus.
Alar Xiloscient misty-stepped into the cavern, which was only otherwise accessible through a tiny tunnel, and found a lime-covered skeleton clutching a large tome, and an emerald easily worth 15,000 gold pieces! Upon reading the tome and identifying the gem, they discovered that the tome was the Dirges of Apollyon and it revealed the ritual for bringing Vetra-Kali back to this plane. The emerald was the first of his three stolen eyes, the Eye of Withering.
With the knowledge of what needed to be done, the villains scryed throughout the Horn, and found everything from a golem in need of repairs, to a secret treasure vault guarded by wraiths, a petrified member of the Sons of the Pale Horseman, to a pair of daemons (Hexor and Vexor), and a lightning elemental. Even Grumblejack discovered his secret daemonic heritage, after drinking from the unholy water produced by the shrine of Vetra-Kali (and growing wings!).
Upon reaching the sanctum, they had gathered all of the Eyes and revived Halthus the Flayer (the petrified cultist) just long enough for him to be the first sacrifice. Upon his death the outside of the Horn burst into unholy green flames, burning away all the vegetation and sending a beacon skyward, revealing the location of the Horn to everyone in Farholde, and possibly farther.