Captain America (1968 series) #148

The hidden mastermind behind Hydra is…the Red Skull! He appears before them via a hologram (which the Kingpin learns to his dismay when he charges the Nazi villain) to explain his latest scheme for world domination: a fifth Sleeper, arising from the nearby desert, spewing deadly nerve gas and wiping out the population of Las Vegas—unless Captain America surrenders to him. Cap flies off by jetpack to try to intercept the Sleeper before it reaches the city limits. Realizing an army may be needed to stop the Red Skull, the Falcon contacts Nick Fury to mobilize a combat force quickly and alerts the Femme Force at Hydra HQ. The Kingpin summons all his mob subordinates in the area to action as well. Sharon Carter leaves her hospital bed to lead the Femme Force, to a jealous Val’s dismay. Cap meets the Sleeper at the edge of the city just as the Femme Force attacks the giant robot. Cap manages to make it inside before the door closes and the Sleeper opens fire on the SHIELD agents and mobsters. As the robot withstands air bombardment, Cap fight his way up to the control room for a showdown with the Red Skull. The Nazi mastermind gets the drop on Cap but the Falcon arrives to overpower the Skull and a blow from Cap sends the villain flying through and open visual slit to his apparent death. The two heroes sabotage the controls and escape before the Sleeper explodes. An agent of the kidnapped millionaire Harold Howard expresses his thanks, and Cap and the Falcon part to go their separate ways.