In2261,theVorlonsjointheShadowWar,buttheirtacticsbeeancernforthealliancewhentheVorlonsbegindestroyingentireplaswhichtheydeemtohavebeen"influenced"bytheShadows.Disturbedbythisturnofevents,Babylon5recruitsseveralotherpowerfulandancientraces(theFirstOnes)totheircause,againstboththeShadowsandtheVorlons.CaptainJohnSheridanreturnstothestationafterescapingfromZ’ha’dum,butataprice:barringillnessorinjury,hehasonly20yearslefttolive.HeisacpaniedbyamysteriousaliennamedLorienwhoclaimstobetheoldestsentientbeinginthegalaxy.HoursbeforeSheridan’sreturn,Garibaldiisrescuedandreturnedtothestation,inratherdubiouscircumstances.HeismarkedlymoreparanoidandsuspiciousofotheralienracesandofSheridanthanhewasbefore.CentauriEmperorCartagiafesarelationshipwiththeShadows.LondoMollariengineerstheassassinationofCartagiaandrepudiateshisagreementwiththeShadows.LondokillsMr.MordenanddestroystheShadowvesselsbasedontheCentaurihomeworld,inanattempttosavehisplafromdestructionbytheVorlons.Aidedbytheotherancientraces,andseveralyoungerones,SheridanluresboththeVorlonsandtheShadowsintoanimmensebattle,duringwhichtheVorlonsandShadowsrevealthattheyhavebeenleftasguardiansoftheyoungerraces,butduehilosophicaldifferences,endedupusingthemaspawnsintheirendlesswarsthroughouttheages.Theyoungerracesrejecttheirntinuedinterference,andtheVorlonsandShadows,alongwiththeremainingFirstOnes,agreetodepartthegalaxyforever.AftertheShadowsaredefeatedGaribaldileaveshispostassecuritychiefandworksonhisownasa"providerofrmation".HebeginsworkingforoneWilliamEdgars,aMarsTyon,whoismarriedtoGaribaldi’sformerlove.WhileheworksevercloserwithEdgars,hebeesincreasinglyaggressivetowardsSheridanandeventuallyleavesBabylon5.MinbarisgrippedbyabriefcivilwarbetweentheWarriorandReligiouscastes.DelennsecretlymeetswithNeroonoftheWarriorcasteandnvinceshimthatneithersidecanbeallowedtowin.Shetellshimthatshewillundergoaritualwhereinshewillbewillingtosacrificeherself,butwillstheritualbeforesheactuallydies.WhenNeroonseesthatsheactuallyintendstogothroughtheentireritual,herescuesherandsacrificeshimselfinstead,declaringthat,althoughhewasbornWarrior,inhisheartheisReligious.AspartoftheongoingnflictbetweenEarthandBabylon5,GaribaldieventuallybetraysSheridanandarrangeshiscaptureinordertogainEdgars’trustandlearnhisplans.GaribaldilaterlearnsthatEdgarscreatedavirusthatisdangeroustoonlytelepaths.Itisthenrevealed,thatGaribaldiwasactuallyabductedbythePsi-CorpsattheendofSeason3andre-programmedbyBesterrovidermationtohimattherighttime.BesterreleasesGaribaldiofhisprogramming,andallowshimtoremembereverythinghehasdonesincebeingkidnapped.Edgarsiskilledandhiswifedisappears,butisreunitedwithGaribaldiaftertheendofthewar.GaribaldihelpsfreeSheridanandreturnhimtothecampaigntofreeEarth.AnallianceledbyBabylon5freesEarthfromtotalitarianrulebyPresidentClarkinashortbutbloodywar.ThisculminatesinClark’ssuicideandtherestorationofdemocraticgovernment.Marsisgrantedfullindependence,andSheridanagreestoresignhismission.TheLeagueofNon-AlignedWorldsisdissolvedandreformedintotheInterstellarAlliance,withSheridanelectedasitsfirstPresidentandntinuinghismandoftheRangers,whoaretoactasagalacticequivalentofUnitedNationspeacekeepers.Intheseasonfinale,theeventsof100,500,1000,andonemillionyearsintothefutureareshown,depictingBabylon5’slastinginfluencethroughouthistory.Amongsttheeventsshownarethepoliticalaftermathofthe2261civilwar,asubsequentnuclearwaronEarthinvolvinganewtotalitariangovernmentintheyearAD2762,theresultingfallofEarthintoapre-industrialsociety,thelossandrestorationofhumanity’sknowledgeofspacetravel,andthefinalevolutionofmankindintoenergybeingssimilartotheVorlons,afterwhichEarth’ssungoesnova.