Last week on the show, the thing many fans feared finally went down. John Walker, the new Captain America, got his hands on some black market super soldier serum and dosed himself, giving him the physical power he so craved to back up the governmental power that now rests behind Cap s iconic shield. Walker s ambition and drive to live up to his vision of what Cap should be, coupled with the newfound strength coursing through his veins, led to an outbreak of savage violence that culminated in him brutally bludgeoning a man to death with the shield in full public view. Sam and Bucky were already inherently suspicious of Walker, his motives and his convictions, and now everything they feared has seemingly been confirmed.