In 1968, Vietnam veteran Lincoln Clay returns home to New Bordeaux and reunites with his surrogate father and Black Mob leader Sammy Robinson, his adoptive brother Ellis, and his friend, Father James Ballard. While initially planning to leave for California, Lincoln agrees to stay and help Sammy, who is facing problems from the Haitian Mob and is indebted to mob boss Sal Marcano. Lincoln ends the conflict with the Haitians by killing their leader and meets with Marcano to see how he can cover Sammy's debts. Although Lincoln declines his suggestion to take over the Black Mob from Sammy, Marcano nonetheless recruits him and Ellis to help his son Giorgi rob the city's branch of the Federal Reserve during the local Mardi Gras celebrations. Aided by their friend Danny Burke, whose father is also looking to settle matters with Marcano after a previous falling out, the group carries out the heist with little complications, but the Marcanos turn on them afterward, killing Sammy, Ellis, and Danny before setting Sammy's bar on fire. Lincoln is also shot and left to die but is rescued by James.

After recovering, Lincoln contacts his former CIA handler John Donovan, who agrees to help for unknown reasons and assists him by locating three crime bosses that also seek revenge against Marcano: new Haitian leader Cassandra, eyeing Delray Hollow, which was taken over by the Dixie Mafia; Danny's father and Irish Mob boss Thomas Burke, whose turf was also given to a rival by Marcano; and exiled Sicilian mafioso Vito Scaletta, who joined Marcano's ranks as part of a deal made with the Commission, but was eventually betrayed and left for dead after Marcano's nephew took over.