Publisher's blurb: The multiverse doors have been opened. Anyone brave enough can slip to a new, unknown world. Adventurers should, however, be prepared for whatever might occur on the other side of the gate... and guard against what might slip through the other way. Miasto pod Kluczem is a fusion of all Fajerbol system worlds into a cohesive multiverse, allowing characters from any game using the system to transit to any other game in the system - not just once, but many times. In particular, five new classes embody the adventurous spirit and possess the powers necessary to successfully flit through the multiverse: międzywymiarowy rozbitek, gwiezdny wojownik, jeździec eteru, poszukiwany w dwunastu wszechświatach, and kontemplator bezmiaru. New inter-dimensional locations, organizations, and monsters are included. But most of all, herein can be found the principles of moving between worlds and surviving the mixing universes that result. Intended for advanced players familiar with the Fajerbol system.