恶第四季

　　1.BokoHaram&UnnaturalSelection:TheNigeriangovernmentisdeterminedtodrivemilitantsfromaterroristgroupoutofthecountry;Anewgene-editingmethodallowscientiststochangethegenetictraitsofplantsandanimalsddd
　　2.EscapetoEurope;CycleofTerror:FollowingtherefugeetrailfromtheSyrianbordertoEurope;TheglobalreactiontotheterroristattackinParisimpactsthefightagainstterrorism.
　　3.RighttoDie:Exploringthemoral,politicalandpersonalquestionsraisedbyeuthanasia.
　　4.BeatingBlindness&WhiteCollarWeed:Doctorsandresearchersmakeincrediblestridesinthefightagainstblindness;Strugglingsmall-scalemarijuanafarmersfacecorporatetakeoversastheendofthepot-prohibitionnears
　　5.Meathooked&EndofWater:Examiningtheenvironmentalharmofindustrialmeatoperations;Assessingthedepthsoftheworld'swatercrisis.
　　6.ReturntoYemen&ChurchandStates:ExaminingtheconflictinYemen;ExploringtheongoingbattleforLGBTequalrightsintheUnitedStates.
　　7.PalestineNowandVivaCubaLibre:ExploringthelivesofyoungPalestinianstoday;ExaminingthepoliticalthawingofrelationshipsbetweenCubaandtheUnitedStates.
　　8.AfghanWomen'sRights&FloatingArmories:ViolenceandoppressionarestillafactoflifeforwomeninAfghanistan;Privatemilitarycontractorsprotectglobalcommerce.
　　9.TheFutureofEnergy:Examiningthefutureofhowtomakeanduseenergyandhowtomeetthegrowingdemandascarbonemissionsarecut.
　　10.TrumpinDubai&ChinainAfrica:TheplightofmigrantworkersinDubai;ExaminingtheincreasinglyprominentbusinessrelationshipbetweenChinaandAfrica.
　　11.TheDeal&CityofLostChildren:ExploringtherecentIrandealfrombothsides;TribesofhomelesschildrenlivealongthetracksinKolkata,India.
　　12.TheEndofPolioandCollateralDamage:HealthworkersputtheirlivesonthelineinPakistantoeradicatepolio;ExaminingthedevastatingeffectsofunexplodedordnanceinMyanmarandLaos.
　　13.StateofSurveillance:ShanetravelstoMoscowtomeetwithEdwardSnowdenanddiscussgovernmentsurveillanceprograms.
　　14.HeroinCrisis&NewAgeofNukes:TheeffectsofAmerica'sHeroinepidemicandthenextnucleararmsrace.
　　15.FlintWaterCrisis&LibyaontheBrink:ExaminingtheeffectsofthewatercrisisinFlint,Mich.;InLibya,rivalmilitiasfighttosavethecountry.
　　16.DieTrying:PatientsandtopresearchersacrosstheU.S.discussrecentmeasurestakentotackleALS;ExploringtheregulatoryhurdlesfacedbyALSpatientsanddrugmakers.
　　17.StudentDebt&FecalMedicine:Thecorrelationbetweenstudent-loanborrowingandthesoaringcostofcollegetuition;Amedicalrevolutioninvolvesusingstoolfromahealthypersontotreatsevereintestinalinfectionsinothers.
　　18.TheNew$paceRace&ClosingGitmo:NASAandagrowingcommunityofprivatecompaniesdecidetoprepareforMarsexploration;Ex-detaineesrevealwhatreallyhappensbehindthewallsoftheAmericanprisonatGuantanamoBay,Cuba.