We did this one without any fighters and it worked out well. We had two bards, a cleric, a sorcerer and a thief. We got into a couple of tumbles -- in the bar, on the docks -- but otherwise talked and sneaked our way through. When it came to the battles, we had a bit of luck with some low rolling enemies and some natural 20s on Bluff checks. I liked the flexibility of the scenario, that we didn't have to fight our way through the entire encounter, and I'm a sucker for the seedier side of the city this one showed.
