If you've ever complained that your grandparents were dull, then you didn't have grandparents like Bernard and Winifred Schlesinger.

In their later years, this secular couple lived in a vicarage that, as their grandson Ian Buruma writes in "Their Promised Land: My Grandparents in Love and War," was "like something out of Agatha Christie." Family members — Buruma's mother was one of five children — were expected to play musical instruments with proficiency. In the Schlesinger household, "the worst possible sin was to be a bore."

Raised in England and proud of it, Bernard and Win, as Buruma refers to them, were also German Jews who "didn't want to make a fuss" about their ethnicity. But Germany did, and, like almost everyone else in Europe, the Schlesingers were involved.

Fortunately for posterity, they wrote thousands of letters to each other in which they chronicled their experiences.

In this exceptional book, Buruma quotes from these letters, which he found in "steel boxes filled with mouse droppings" in the Sussex country house of his uncle, "Midnight Cowboy" director John Schlesinger. Buruma focuses on their correspondence from shortly before World War I — when Bernard was a stretcher bearer in France and Win served as a nurse — until 1946.

Most of the letters quoted here address family matters, jobs and war. Bernard and Win wrote about the world's horrors, but often indirectly. In his correspondence from the Somme, Bernard mentioned the disgusting bully beef fed to soldiers but not the carnage he witnessed.

"Their Promised Land," by Ian Buruma.

References to anti-Semitism were oblique, but both referred to situations in which their ethnicity cost them opportunities, as when hospitals rejected Bernard for physician jobs because he "seemed a little foreign."

Bernard and Win weren't always open-minded about other cultures.

"The average Indian has a child's mentality," Bernard wrote in 1942 from India, where he inspected military hospitals for the Raj. "Pansy" was their favored term for homosexuals, including John, whose childhood habit of putting on shows was, in their view, a "character defect," an assessment they maintained until he became famous.

But Bernard and Win were capable of great kindnesses, most notably when they took in 12 young refugees after Kristallnacht and, in 1946, when they invited two of Hitler's former soldiers to share Christmas dinner with them.

Buruma spends more time on the war part of his subtitle than the love, but the glimpses of tenderness are among the book's most moving passages. "I shall be thinking of you all the time with the most loving wishes," Win wrote to Bernard at the start of World War II.

Think about each other they did, for almost 60 years, in a remarkable romance that their grandson has commemorated with this beautiful book.

Michael Magras is a member of the National Book Critics Circle. His work has appeared in the Chicago Tribune, San Francisco Chronicle, Houston Chronicle and other publications.