We went down the tunnel and ran into a checkpoint. We name dropped Mercy, and explained who we were looking for. Despite our disguises, we seem to have checked out, as they escorted us further in. There were quite a few traps they led us around, which made sense as we eventually learned that the band was the former thieves guild, led by an older elf named Jade.
They had quite a bit of wounded and sick. They also seemed inordinately proud of their success, which I thought was odd because the monsters didn't seem to think the Green Hand existed. When I called them on it, one of the younger guys got defensive; I must have hit a nerve.
We eventually got to meet both sides of the Stonal/Donal coin. He was serving as a cleric helping their injured. We suggested we could setup a meeting with his brother, who was desperate to hear from him, but he didn't want to leave his post. At some point it was suggested we evacuate the non-combatants, which they said would be fine if they had guarantees of safety.
Our discussions were cut short by Kobold-wave attacks by golden-eyed beasts swarming out of the depths. We protected their engineers long enough for them to blow open a wall and release the river, putting a foul barrier between the two warring factions.