Susan Stessin-Cohn and Ashley Hurlburt-Biagini read from and discuss their new book, “In Defiance: Runaways from Slavery in New York's Hudson River Valley, 1735-1831.” It is a valuable collection of fugitive slave advertisements that tells much about the lives of self-emancipated blacks in the rural North. Focusing on the Hudson River Valley, the editors uncover a persistent, local slavery, with national implications. A conversation with Thomas Chulak from the bookstore and Q & A follow a brief reading.