So, the gnomes and co. lived in the dungeon for a few years, continuing to harvest the fungus for trade and digging out some more room for themselves. Their digging eventually attracted the attention of a hive of Formians, though, who chased the former slaves from their lair and started taking the fungus for themselves.
The gnomes wanted their home back, so they used the bulk of their wealth to hire an adventuring party to drive the Formians out. The adventurers weren't quite up to the task, though. They managed to kill some warriors and a Taskmaster, which had been using a dominated krenshar to defend the lair, but they took many wounds in the process. The elf Himool broke his leg and could not make it out of the dungeon, so he elected to stay behind while the group looks for a cleric. They barricaded two of the doors to the room he is in, and he covers the last with his bow, ready to skewer any Formians that poke their heads into the room.
So here are the elf's room, the Formians' entry point, and another shot of the entire dungeon.