Well, things were pretty interesting throughout last night, though I think the group would have preferred to teleport straight to the BBEG rather than slog through the dangerous city streets. They first flew across the lake to land at a small dock. They were a bit taken aback by the carnage around them, but had little time to react as flaming rocks smashed around them from the sky, from which emerged several fire elementals. They were brimming with fire resistance, which helped, and had little trouble dispatching these things. Various dangers chipped away at their protections, and they dealt with backdraft/explosions quite well when they had to enter one of the buildings. They crossed a moat of magma - several flew, while others skipped across crumbling stone slabs. The conflaguration ooze ambush happened in the middle, but the two party members who crossed on foot had ridiculous ACs - still one did take some "Fire in the Blood" damage, which had the desired frightening effect (they had seen a native of the city die horribly in this way). They made it to the other side, and as a whole were relatively unscathed, but the sorceror is now quite low on spells. We stopped 3/4 of the way to the BBEG, as the combats took a long time. Thanks to everyone for their suggestions - it made the trek through the city far more exciting than what I had originally planned.