According to his publisher, Benjamin Black (under which name Irish writer John Banville writes popular crime novels) “has good information” that the English princesses, Elizabeth and Margaret, were smuggled out of England during the London Blitz and hidden away in neutral Ireland. No friend to “perfidious Albion” and infested by IRA boyos and German operatives, Ireland strikes one as just the wrong place for the heir to the British throne and her sister.

Still, it’s a fine set up for “The Secret Guests” and, to this end, Black bundles off Elizabeth, 14, and Margaret, 10, to the Tipperary countryside and settles them in Clonmillis Hall, the moldering “big house” of Sir William Ormonde, the Duke of Edenmore. Bearing the assumed names Ellen and Mary, the sisters are accompanied by Detective Garda, St. John Strafford, a rare Protestant in the Irish police force, and British Special Branch agent Celia Nashe, who, though issued with a Browning automatic, does not appreciate the role of de facto babysitter.

Although the novel produces eventual gunfire and a dead body or two, the plot, such as it is, is more a series of episodes through which Black demonstrates his deftness in evoking milieu, ambience, and the points of view of several mordantly drawn characters. Among them is Richard Lascelles, a supercilious British Embassy official whose snooty opinion of the Irish includes the Garda — or, in his view, “Paddyland’s pretend police force … a gang of pensioned-off gunmen pressed into blue serge uniforms and told to behave themselves.”

Over lunch at the Kildare Street Club, haunt of the moribund Anglo-Irish “ascendancy,” Lascelles reaches an agreement with a canny Irish Minister whereby, in exchange for shipments of coal, Ireland will accept the princesses and provide protection. Thus we find President Eamon de Valera’s son, Vivion, commanding the army detail deployed to defend the estate and its visitors.

Of the two royals, Margaret (Mary) is, unsurprisingly, the winner; she is a sly, contrary little girl, “tough as tacks,” whose high birth does not preclude low snooping into other people’s private affairs. Her sister, Elizabeth (Ellen), is serious, dutiful and a closet romantic. Their host, Sir William, an ex-military old duffer, lives under the thrall of his iron-willed housekeeper, Mrs. Hanlon, “a low-sized almost square-shaped woman.” Close by, in the neighboring town, Tom Clancy, preposterous self-styled boss of the local IRA, makes the unfortunate decision to call down two heavies from Belfast and the action finally hots up. If this story cannot be found in history, it is an entertaining conceit — and feeds our own republic’s unappeasable appetite for the Royals.

Katherine A. Powers, a Minnesota native, reviews for the Washington Post, the Wall Street Journal and elsewhere.

The Secret Guests
By: Benjamin Black.
Publisher: Henry Holt, 291 pages, $27.