Based on Colson Whitehead's book of the same name, "The Underground Railroad" chronicles young Cora's (Thuso Mbedu) journey as she makes a desperate bid for freedom in the antebellum South. After escaping her Georgia plantation for the rumored Underground Railroad, Cora discovers no mere metaphor, but an actual railroad full of engineers and conductors, and a secret network of tracks and tunnels beneath the Southern soil.