In the aftermath of the explosion on Z'ha'dum, Sheridan is presumed dead and Garibaldi is missing. Delenn struggles to keep the alliance against the Shadows together, and Londo takes up his new position on Centauri Prime as security advisor the emperor.
Babylon 5 is a five-mile long space station located in neutral space. Built by the Earth Alliance in the 2250s, it's goal is to maintain peace among the various alien races by providing a sanctuary where grievances and negotiations can be worked out among duly appointed ambassadors.
A council made up of representatives from the five major space-faring civilizations - the Earth Alliance, Minbari Federation, Centauri Republic, Narn Regime, and Vorlon Empire - work with the League of Non-Aligned Worlds to keep interstellar relations under control. Aside from its diplomatic function, Babylon 5 also serves as a military post for Earth and a port of call for travelers, traders, businessmen, criminals, and Rangers.