NCIS star Mark Harmon is back with another real-life intelligence thriller. Co-written with former special agent Leon Carroll Jr., Ghosts of Sicily is the third installment in their acclaimed “Ghosts of…” book series and will be released on April 14, 2026.
Following Ghosts of Honolulu and Ghosts of Panama, the new book uncovers a little-known World War II operation in which U.S. Naval Intelligence secretly collaborated with the Mafia to combat Nazi threats and protect America’s ports. Publishers have already hailed it as the strongest entry in the series to date.
Inspired by his years portraying Leroy Jethro Gibbs on NCIS, Harmon has been passionate about revealing the untold history of the agency. With Carroll Jr.—a former NCIS agent and the show’s longtime technical advisor—the book sheds light on classified missions and lost records that shaped modern naval intelligence.
