Five contemporary black women in the Kansas City area take a weekend train trip to St. Louis as part of the book and wine club they are in together. Marie, a librarian, in addition to arranging the trip, is also doing research for the memory book she is putting together for her grandmother's 80th birthday. Part of Marie's research involves looking through "The Negro Motorist Green Book,” the guidebook used by African-Americans in pre-segregation America to know the safe and welcoming places to stay and patronize while traveling. Marie accidentally time travels to the 1940s, where she stays in a boarding house mentioned in the “Green Book”. (The four women in the boarding house are also played by actresses playing Marie's friends on the train trip.) Marie discovers family secrets as well as gets an up-close view of how the present and the past compare, contrast, and converge.