Author Diana McCaulay discusses her book “Dog-Heart,” the story of a middle-class single mother who takes a boy from the Jamaican ghetto under her wing. The book explores complexity of relationships between two people from very different backgrounds and the challenges faced by those seeking social change. 8 p.m. Books & Books, 265 Aragon Ave., Coral Gables. Details: (305) 442-4408 or www.booksandbooks.com.