Papers! Papers!

As the monk stepped out into the darkness, nets and clubs rained down as a gang of slavers decided to try and improve their stock levels. Soon most of the party were trading blows with the slavers and trying to escape from entanglement, the latter hindered by a need to keep the adventurers alive. The combat was soon very one-sided and the remaining attackers tried to run off into the night, only to find that a monk in a net can STILL keep up with them (until he gets bored, that is). The scout cut one escapee down while the druid and wolf team took out a second, leaving the third to disappear into the darkness.
The druid used a neat trick to chase his prey - he changed into an eagle and, holding a sun rod for illumination, flew after the running slaver. Unfortunately, flying orbs of light are not very common in the desert at night and keen eyes scanning the sands from on high came to investigate.
The bat-winged devil landed in front of the adventurers, or more accurately "curfew breakers", and demanded to see their papers - if which they had none. Pretending to be the same people as named on the slavers' documents cut no ice with the baatezu and the party were commanded to report to the tower immediately.

Experience
8 tiefling slavers - 600 xp per character