UnseenEnemyisanessentialexplorationofreasons21st-centurypopulationsareexperiencingarashofdiseasesthatwereonceonlyoutbreaks,buthavenowbecomefull-blownepidemics.Thisincreasedriskthatweface,andthewayssocietyandindividualscanworktogethertoreducethatrisk,areexplainedtothepublicthroughthecasestudiesofthreeepidemics:Ebola,influenzaandZika.Movingacrosstheglobe,wemeetdoctors,diseasedetectivesandeverydaypeoplewhohavesteppedintothehorrorofanepidemicandemergeddeeplychanged.Epidemicsbringoutthebestandworstofhumanbehavior,witheffectsreachingfarbeyondthetollsofsicknessanddeath.