Either Cryptomancer Nasrara or Investigator Dahno, on behalf of their respective factions, have sent you to clear out the recently unearthed Underrot Caverns. The passageways within are too narrow to bring a full group and as such you must travel alone. But at least all the loot will be yours!
The objective is to kill everything in sight. There are three different themes of monsters that are chosen randomly each time you enter: undead, beasts, or gargoyles. All three themes drop the same loot. Named monsters can also spawn, but they are not guaranteed to appear.