Ghosts haunt the project of building an airport in Saint Helena, a remote Atlantic isle where Napoleon died in exile. Project consultant Annina Van Neal discovers the site covers a mass grave of thousands of African slaves. She further finds out that the sovereign, Britain, has been concealing it for centuries. Motivated by her guilt for contributing to the project, she teams with conservation expert Peggy King Jorde, and tells the world about one of the last remains of the massive Atlantic slave trade. Facing a wall of indifference and suspicion, they struggle to commemorate the victims and turn the airport into a world heritage site.