Black scuba divers across the world search for buried shipwrecks from the transatlantic slave trade, when millions of enslaved Africans were trafficked to the Americas during the 15th to the 19th centuries. A six-part podcast series, Into the Depths, follows National Geographic Explorer Tara Roberts as she sets off on the journey of a lifetime to meet the divers and marine archeologists, descendants of those brought over on ships, and historians investigating the lost stories of the slave trade—both to expand the historical record and to honor the estimated 1.8 million souls who perished during the Middle Passage.