The film purports to recreate the James-Younger Gang's most infamous escapade, the September 7, 1876, robbery of "the biggest bank west of the Mississippi", in Northfield, Minnesota.

In the mid 1870s, outlaws Jesse James, Cole Younger and their brothers are granted amnesty by the Missouri legislature, sympathetic to the troubles created for all citizens by the American Civil War.

The bankers victimized by the James and Younger gangs are vehemently opposed to this action and hire a Pinkerton agent to follow the outlaws' every move.

Jesse, Frank, and their men arrive on horseback and, together with Cole, persuade the locals that a gold shipment is on its way to the bank because it is supposed to be the safest possible place for it.

Teller Heywood, having discovered the "gold shipment" is bags of rocks;assumes Wilcox is part of the robbery and refuses to open the time-lock vault.