Inside the bank, the half-witted Crazy Lee (Bo Hopkins), one of the gang members purposely (or thoughtlessly) left behind o guard hostages "until after the shooting starts," terrorizes wo bank clerks and a female customer." They acquired submachine guns, ammunition, a Geiger counter, pistols, and other supplies.They approached the desolate, silent, dead and ruined city, described solemnly by Virgil as "like a storm at sea, but solidified," with twisted, melted and charred wreckage.He first rescued trapper workers on a roof, and then was told by one of the White-Coated lab Scientists (Pat Starr) that vials of Beltric acid, if heated up to over 180 degrees, would create a major crisis: the production of clouds of corrosive vapor could cover the entire Eastern seaboard - "If it begins to heat up, it""ll turn volatile.To restore the original Hill Valley to its better state, "Doc" and Marty had to travel back to the year 1955 to the time of Marty""s and "Doc""s" previous visit (in the first film) - November 12, 1955 - the date that older Biff gave his younger counterpart the almanac, and prevent the incident from happening.When seen by American audiences in the early 1940s during the progress of World War II, the implication was obvious hat Hitler""s evils in Europe could also inhabit the ethos of the sacred American/western frontier.