From the publisher's website:
Metropolis Rho is a fully developed adventure and location sourcebook for the post-apocalyptic role-playing game, Darwin's World 2nd Edition. It intended to introduce players to the setting of Darwin's World in a unique new way.
Metropolis Rho is designed specifically to give gamemasters an idea of the potential of even the most sketchy community descriptions presented in the Darwin's World rules. At its most basic, the sprawling city depicted in this campaign setting is really just a Degenerate community (one of the examples given in the rulebook is, in fact, based on this very city), but by fleshing it out the idea seed quickly turns into a truly dynamic environment in which to adventure.
Metropolis Rho goes far beyond a the simple definition of a Degenerate society; herein it becomes a real, living city and campaign setting, a launching point for future adventures in the radiated wasteland of the Twisted Earth.
The complete series of adventures should take characters from 1st to 8th level.