▁one ▁of ▁J ex ' s ▁experiments . ▁He ▁has ▁sought ▁ven ge ance ▁and ▁killed ▁all ▁but ▁J ex . ▁Though ▁he ▁cannot ▁harm ▁innoc ents ▁by ▁his ▁programming , ▁the ▁G uns ling er ▁war ns ▁that ▁J ex ▁must ▁be ▁brought ▁to ▁him ▁or ▁he ▁will ▁take ▁more ▁dr astic ▁measures . ▁ ▁The ▁Doctor ▁returns ▁to ▁town , ▁and ▁an gr ily ▁drag s ▁J ex ▁to ▁face ▁the ▁G uns ling er . ▁Amy ▁as ser ts ▁that ▁the ▁Doctor ▁has ▁changed ▁for ▁the ▁worse ▁from ▁months ▁of ▁trav elling ▁on ▁his ▁own . ▁J ex ▁ple ads ▁that ▁he ▁has ▁at oned , ▁but ▁the ▁cy borg ▁prepar es ▁to ▁kill ▁him . ▁Isaac ▁push es ▁J ex ▁out ▁of ▁the ▁way ▁and ▁takes ▁the ▁le th al ▁shot . ▁As ▁he ▁dies , ▁Isaac ▁gives ▁the ▁Doctor ▁his ▁mar shal ▁bad ge ▁and ▁has ▁him ▁promise ▁to ▁protect ▁Mer cy . ▁The ▁G uns ling er ▁dep arts , ▁warning ▁he ▁will ▁return ▁for ▁J ex ▁at ▁no on ▁tom orrow . ▁ ▁J ex ▁tells ▁the ▁Doctor ▁he ▁is ▁rem or se ful ▁for ▁all ▁those ▁death s ▁his ▁work ▁has ▁caused . ▁The ▁towns folk ▁demand ▁the ▁Doctor ▁turn ▁J ex ▁over , ▁but ▁he ▁rem inds ▁them ▁that ▁Isaac ' s ▁death ▁will ▁be ▁for ▁n aught ▁if ▁they ▁do ▁so , ▁and ▁has ▁come ▁up ▁with ▁a ▁plan ▁from ▁learning ▁about ▁J ex ' s ▁society . ▁When ▁the ▁G uns ling