Colm Tóibín’s 2009 novel “Brooklyn” told the story of a meek young Irishwoman, Eilis Lacey, who emigrates to New York in the 1950s out of a sense of familial obligation and slowly, diligently begins building a new life for herself. A New York Times best seller, the book was also adapted into an Oscar-nominated movie starring Saoirse Ronan — and now, 15 years after its publication, Tóibín has surprised himself by writing a sequel.“Long Island,” his new novel, finds Eilis relocated to the suburbs and, in the opening scene, confronting a sudden crisis in her marriage. On this week’s podcast, Tóibín talks to Sarah Lyall about the book and how he came to write it.