Kwame Alexander's new novel aimed at teens, The Door of No Return, focuses on the history of slavery. It follows a boy growing up in Ghana in 1860, and it aims to help readers understand the wholeness of the lives and experiences of Africans before they walked through that "door of no return" – and were shipped to the Americas. In an interview with NPR's Rachel Martin, Alexander talks about how he used poetry to make the heavy subject palatable for children.