The Spanish Diplomat’s Secret

Anglo-Indian private investigator Jim Agnihotri and his wife, Lady Diana, have their 19th-century ocean liner journey from the U.S. to England interrupted by theft and murder in March’s convoluted sequel to 2022’s Peril at the Exposition. With only a week until the ship reaches port and no plausible way on or off, guests are rattled when the Spanish ambassador to the U.S., Don Juan Nepomuceno, is found murdered and missing a case of jewels. A short time later, young Alice Fry also turns up dead, an apparent suicide—though some traveling with her insist she was the victim of a supernatural curse—and Jim and Diana decide to investigate. March provides a classic locked-room mystery setup, but fails to winnow down the suspects early enough, causing the plot to drag—Jim reiterates his purpose (“My mind returned to my present conundrum; who’d murdered the Spanish don, and why?”) one too many times as he wades through a sea of red herrings. He’s an amiable hero, with a rich backstory as a soldier in the British Indian army, but Diana is unevenly drawn, by turns an overeager partner (“We have to catch this maniac!”) and a woman prone to “dark malaise.” Still, historical mystery fans will relish March’s well-integrated maritime research and echoes of such Christie classics as Murder on the Orient Express. Despite this lackluster entry, there’s hope for the series yet. (Sept.)