John F. Kennedy's assassination launched a frantic search to find his killers. It also launched a flurry of covert actions by Lyndon Johnson, Robert F. Kennedy, and other top officials to hide the fact that in November 1963 the United States was on the brink of invading Cuba, as part of a JFK-authorized coup. The coup plan's exposure could have led to a nuclear confrontation with Russia, but the cover-up prevented a full investigation into Kennedy's assassination, a legacy of secrecy that would impact American politics and foreign policy for the next 45 years. It also allowed two men who confessed their roles in JFK's murder to be involved in the assassination of Dr. Martin Luther King, in 1968. Exclusive interviews and newly declassified files from the National Archives document in chilling detail how three mob bosses were able to prevent the truth from coming to light -- until now.