Freedom Cry

Freedom Cry is a single-player downloadable content addition for Assassin's Creed IV: Black Flag. The content is available with the purchase of the Season Pass or as a standalone purchase.

Official synopsis
Born a slave, Adéwalé found freedom as a pirate aboard the Jackdaw'' as Captain Edward Kenway’s second-in-command. Fifteen years later, Adéwalé has become a trained assassin and finds himself shipwrecked in Saint-Domingue with no weapon nor crew, starting a new adventure of his own.'' - Ubisoft.

Reference

 * Freedom Cry announcement trailer