Single player DLC for Black Flag - Freedom Cry - will be released for download on December 17th.
The boys over at VideoGamer spotted the date adorning a magazine advert in the latest issue of Game Informer.
Freedom Cry is a nine mission self-contained story featuring Edward Kenway's first mate Adewale, and Ubisoft's given some info on the story:
"Born a slave, Adewale found freedom as a pirate aboard the Jackdaw as Captain Edward Kenway's second-in-command. Fifteen years later, Adewale has become a trained assassin and finds himself shipwrecked in Saint-Domingue with no weapon nor crew, starting a new adventure of his own."
You'll be able to buy the DLC separately or download it as part of the game's Season Pass.