We found a ship to take us cruising down the river, as it would be quicker to travel. There are ginormous crab creatures that might eat the entire crew in that river, but we'll be okay, right? There are only claw marks and stuff that we can see, and maybe it would be advisable to not be trapped on a boat going down a river?
Turns out the big crabs are intelligent and can be hurt and disabled, but that they stop bleeding when they're in water. Their claws are tough as hell, but you can defeat them. The party - sans Murmei and Knightlight, who were hiding out downstairs, because water would be bad for a Flame Servant - fight off two of said crabs.
We made it safely to the town of Kurun, where we possibly dodged several side quests - and assassins? We didn't stay for very long, as we were busy trying to get back to Thistle Hold. Which we eventually did. Huzzah! Because all of this had actually been a side quest, and not part of the actual campaign! D'oh ...