In which the Order of the Stick gets plotting -- it does continue what was started with the first one, so there are spoilers for that ahead -- and (ta-da!) leaves the dungeon. I note that Burlew's commentary on the story is interesting, but does also contain spoilers, so you may want to skip them unless you've followed it online and know who's who.
The last page of Dungeon Crawlin' Fools exploited dramatic irony to the hilt by showing that the things they were certain they had done were -- not quite so final as they thought. So in town, the important interaction is keyed by the escaped Linear Guild, and leads to a side quest in the best tradition.
Meanwhile, a mysterious figure in blue is tracking them.
Two subplots show the Linear Guild and Xykon both recuperating from their losses to become serious menaces again. And the Order ends up heading south. It involves Durkon interpreting Thor's will in a storm, Belkar taking a level in barbarian, assassins with standards enough to avoid killing innocent bystanders, one reason why Haley wants the gold (besides being greed), her reaction to losing treasure, and an old man with a cat.