Ateamofelitecaversledby68-yearoldBillStoneattemptsamonths-longexpeditiontoofficiallymakeCheveCaveinOaxaca,Mexicotheworld’sdeepestcave.Amassivelogisticalundertakingabovegroundsupportstheleadteaminthedepthsastheynavigateanundergroundmazeoftwistingtunnelsanddeadendsinsearchofapassagethatleadstothebottomofdeepestcaveonearth.