There's a summons for you from Port Royal. There's a job to be done. A convoy smuggling gold is leaving Havana, and Morgan's on it. That's all they said, apparently they think you'll know what needs to be done.
Note: A bribe of 1M is required to enter Port Royal to players lacking in sufficient notoriety (unless it is Epic Pirate Feud, where entry to pirate towns is free of charge to all).