The film is set in 1970's and follows the titular Black Dynamite, a Vietnam veteran and former CIA agent who vows to clean up the streets of drug dealers and gangsters after his younger brother Jimmy is killed by a shady organization. O'Leary, Black Dynamite's former Army and CIA partner, reinstates him into the agency because they do not want him seeking vengeance by himself. While trying to get to the bottom of Jimmy's murder, he finds out that his brother was actually working undercover for the CIA...