In the previous session the group started to collect the materials needed by the drow archmage Vizeran to banish the demon lords back into the abyss. In this session they continued this "shopping list", moving into an area of the Underdark called The Labyrinth.

On the way there they encountered a large cave with a strange tower made completely out of adamantium in it. It became quickly obvious that the tower was magic, and while there were a door at the bottom and a trap door on the roof, there was no way to open those. Finally Mog'burz teleported inside through the arrow slits with his Misty Steps spell. However the tower wasn't empty, so he got attacked by a Boneclaw, which is basically an undead monster that is created when some mage tries to attain lichdom and horribly fails. Arkoy then teleported the other group members into the tower, although they ended up on the wrong floor due to the randomness of the teleport spell. The group killed the Boneclaw, and found the diary of the mage describing how he wanted to become a lich. The diary also told them that the tower was a Daern's Instant Fortress magic item, and gave them the activation words so they could open the doors, and turn the tower into a small cube and back into the tower. I did drastically reduce the damage the tower does when he grows from the cube, because otherwise nobody uses the thing as a building, but only uses it as a reusable fireball kind of effect.

Then the group came to the entrance of The Labyrinth, decorated with two piles of heads, and scrawlings in blood praising Baphomet. Surina used the Stonespeaker Crystal to try and talk to the freshest head with Speak with Dead; but as the crystal had become infused in Gravenhollow with the power to grant visions, she learned about the eternal war between Baphomet and his minotaur followers against Yeenoghu and his gnoll followers. She also learned that a goristro servant of Baphoment was hunting in The Labyrinth, at the same time as Yeenoghu himself with some gnolls.

Now the group could have staged the two hunting parties meeting each other, but instead they went for the simpler plan to attack the two parties separately. The goristo and the minotaurs was a tough fight, but they killed him and got his heart for the ritual. Yeenoghu with his gnolls was much, much harder, especially with him advantage on saves against spells, innate spellcasting, legendary resistance (which is automatic success on saving throws), and legendary actions (actions done outside his turn). Even with the help of amulets of protection from demons the group just managed to wound him with two arrows, grab the arrows with his blood on it (which they needed for the ritual), and flee by teleporting away. Yeah, high level groups teleport a lot.

Using a Find the Path spell they then found the gallery of angels, where eight angels were petrified for eternity for sins they had committed. This was a fun little encounter, because the angels can't be liberated, but afflict anybody touching them with various effects. Besides Mog'burz getting temporarily charmed and hitting Arkoy, nothing serious affected the group; although Quarion was much spooked by an angel telepathically asking him repeatedly to kill him (which is impossible) and not shutting up about it (fortunately the effect only has the same range as a voice). They managed to get a petrified feather from each angel, and thus now have all the ingredients for their ritual. As a bonus they could ask the angels a question, twice, and asked the same question twice: Will Vizeran betray them? They got twice the same answer, that it isn't them that Vizeran wants to betray or harm.

After bringing all the ingredients to Vizeran, the group must now wait for the Dark Heart to be assembled by the drow archmage. But in the meantime they got a call for help from the ruler of Neverlight Grove, Basidia: Zuggtmoy has finally arrived in the Underdark region known as Araumycos, which is basically a continent-sized fungal lifeform. There she plans to hold a "wedding" between her and Araumycos, which would give her control over him and the whole area. The group is called to prevent that, which is what we plan to play in the next session, The Fetid Wedding.