In2261,theVorlonsjointheShadowWar,buttheirtacticsbecomeaconcernforthealliancewhentheVorlonsbegindestroyingentirelanetswhichtheydeemtohavebeenquot;influencedquot;bytheShadows.Disturbedbythisturnofevents,Babylon5recruitsseveralotherowerfulandancientraces(theFirstOnes)totheircause,againstboththeShadowsandtheVorlons.CatainJohnSheridanreturnstothestationafterescaingfromZ’ha’dum,butatarice:barringillnessorinjury,hehasonly20yearslefttolive.HeisaccomaniedbyamysteriousaliennamedLorienwhoclaimstobetheoldestsentientbeinginthegalaxy.HoursbeforeSheridan’sreturn,Garibaldiisrescuedandreturnedtothestation,inratherdubiouscircumstances.HeismarkedlymorearanoidandsusiciousofotheralienracesandofSheridanthanhewasbefore.CentauriEmerorCartagiaforgesarelationshiwiththeShadows.LondoMollariengineerstheassassinationofCartagiaandreudiateshisagreementwiththeShadows.LondokillsMr.MordenanddestroystheShadowvesselsbasedontheCentaurihomeworld,inanattemttosavehislanetfromdestructionbytheVorlons.Aidedbytheotherancientraces,andseveralyoungerones,SheridanluresboththeVorlonsandtheShadowsintoanimmensebattle,duringwhichtheVorlonsandShadowsrevealthattheyhavebeenleftasguardiansoftheyoungerraces,butduetohilosohicaldifferences,endeduusingthemasawnsintheirendlesswarsthroughouttheages.Theyoungerracesrejecttheircontinuedinterference,andtheVorlonsandShadows,alongwiththeremainingFirstOnes,agreetodeartthegalaxyforever.AftertheShadowsaredefeatedGaribaldileaveshisostassecuritychiefandworksonhisownasaquot;roviderofinformationquot;.HebeginsworkingforoneWilliamEdgars,aMarsTycoon,whoismarriedtoGaribaldi’sformerlove.WhileheworksevercloserwithEdgars,hebecomesincreasinglyaggressivetowardsSheridanandeventuallyleavesBabylon5.MinbarisgriedbyaiefcivilwarbetweentheWarriorandReligiouscastes.DelennsecretlymeetswithNeroonoftheWarriorcasteandconvinceshimthatneithersidecanbeallowedtowin.Shetellshimthatshewillundergoaritualwhereinshewillbewillingtosacrificeherself,butwillstotheritualbeforesheactuallydies.WhenNeroonseesthatsheactuallyintendstogothroughtheentireritual,herescuesherandsacrificeshimselfinstead,declaringthat,althoughhewasbornWarrior,inhisheartheisReligious.AsartoftheongoingconflictbetweenEarthandBabylon5,GaribaldieventuallybetraysSheridanandarrangeshiscatureinordertogainEdgars’trustandlearnhislans.GaribaldilaterlearnsthatEdgarscreatedavirusthatisdangeroustoonlyteleaths.Itisthenrevealed,thatGaribaldiwasactuallyabductedbythePsi-CorsattheendofSeason3andre-rogrammedbyBestertorovideinformationtohimattherighttime.BesterreleasesGaribaldiofhisrogramming,andallowshimtoremembereverythinghehasdonesincebeingkidnaed.Edgarsiskilledandhiswifedisaears,butisreunitedwithGaribaldiaftertheendofthewar.GaribaldihelsfreeSheridanandreturnhimtothecamaigntofreeEarth.AnallianceledbyBabylon5freesEarthfromtotalitarianrulebyPresidentClarkinashortbutbloodywar.ThisculminatesinClark’ssuicideandtherestorationofdemocraticgovernment.Marsisgrantedfullindeendence,andSheridanagreestoresignhiscommission.TheLeagueofNon-AlignedWorldsisdissolvedandreformedintotheInterstellarAlliance,withSheridanelectedasitsfirstPresidentandcontinuinghiscommandoftheRangers,whoaretoactasagalacticequivalentofUnitedNationseacekeeers.Intheseasonfinale,theeventsof100,500,1000,andonemillionyearsintothefutureareshown,deictingBabylon5’slastinginfluencethroughouthistory.Amongsttheeventsshownaretheoliticalaftermathofthe2261civilwar,asubsequentnuclearwaronEarthinvolvinganewtotalitariangovernmentintheyearAD2762,theresultingfallofEarthintoare-industrialsociety,thelossandrestorationofhumanity’sknowledgeofsacetravel,andthefinalevolutionofmankindintoenergybeingssimilartotheVorlons,afterwhichEarth’ssungoesnova.