The Green Gems continued the exploration of the ancient city. Making way to the Mindflayer-built tower through the skeleton-infested ruins, they encountered a gnome, looking for his gem. Bebe tried to read his mind and went bonkers, as the gnome was in reality a Death Slaad, creature of chaos and destruction. A fight followed, straining the Green Gems to their breaking point.
With the creature dead, they continued towards the tower. There they found evidence (mosaics) that the Yuan-ti god was not a god, but in reality a demon the Yuan-ti had tricked the serpent-men into worshiping. It was also, according to the info, trapped on a far away plane and not in a volcano, as the Yuan-ti seemed to think.
In the basement, they fought a Guardian Naga, who turned out to protect/guard a huge room full of thousands of Soulless Ones, all standing in neat rows, seemingly in trance. The Green Gems barely managed to sneak past them without waking anything and found another room, where a rod once had been kept. Probably the control-rod seen on murals earlier.