From publisher blurb:
Return To The Lost City (Secrets of The Second Dome) is an adventure for Darwin's World 2nd Edition that returns to the unique subterranean environment first introduced in [The Lost City]. In Return To The Lost City the player characters go back to the sunken ruins of the Bakersfield dome complex following the rumored disappearance of a peaceful colony of settlers, who - lulled into a false sense of security by stories of the party's success against the raiders of the Lost City - established a community precariously close to the cavern's rift entrance. Gathering their strength the heroes who first explored the Lost City and survived its perils return, this time to investigate the brutal massacre of a peaceful community and put the danger of the Lost City's terrible troglodilian inhabitants to rest once and for all.
A party of four to six characters of levels 9-11 should be able to meet and deal with the new and rising dangers of the Lost City. As a continuation of the original adventure, many of the weaker dangers have been wiped out - leaving far more powerful foes to contend with! It is intended that the same characters who went through the first adventure should also go through the second, but there is little in the adventure that relies on the party having been here before (except for a few easily ad-libbed location descriptions).