Just Cause begins with Rico Rodriguez, an operative for an organization known as the Agency, being dropped into a Caribbean tropical island called San Esperito, after being called there by his commanding officer (CO), Tom Sheldon, to help overthrow San Esperito's dictator; Salvador Mendoza, whom the Agency believes to be in possession of weapons of mass destruction (WMDs). After his arrival, Rico rendezvouses with Sheldon, as well as their partner and fellow agent Maria Kane, and they ally themselves with a faction of guerrilla freedom fighters. Rico assists them in their civil war against Mendoza's corrupt officials, and also assists in the liberation of various territories to further destabalize the government's rule over the island.