NEW YORK (AP) — The bestselling author team of Marie Benedict and Victoria Christopher Murray has a new novel in the works, while celebrating a milestone for its best-known publication, “The Personal Librarian.”

Benedict and Murray are writing a historical thriller set in 1930s New York, featuring such real-life characters as the gangster Lucky Luciano and the Black assistant district attorney Eunice Hunton Carter and the “notorious madam” who “forge a bold and unlikely alliance.” The book is currently untitled, and no release date has been set.

“Together, they navigate the treacherous underworld of corruption and vice to bring down the New York City crime syndicate,” the authors said in a statement released Monday through Berkley, a Penguin Random House imprint.

Meanwhile, “The Personal Librarian” has now sold 1 million copies, Berkley announced. Published in 2021, the novel tells the story of J.P. Morgan's personal librarian, Belle da Costa Greene, a Black woman who secretly passed for white. She is currently featured in an exhibition at Manhattan's Morgan Library, “Belle da Costa Greene: A Librarian’s Legacy.”

Benedict and Murray have also collaborated on a bestseller from 2023, “The First Ladies,” about the friendship between Eleanor Roosevelt and civil rights activist Mary McLeod Bethune. The authors each have published numerous books on their own.