After a considerable detente between novels, de Polnay -- an all too agreeable entertainer with a decorator eye for the times, then and now, has told a story within a story and laminated a romance upon a romance. Vincent Warren -- historian, reviewer, publisher's reader -- and Una Nichols, sent by an auction house to appraise the contents, find themselves in Mounge Hall, Suffolk, which is about to be pulled down. Very different to begin with (Vincent conventionally lives with a mother; Una with a photographer always either stoned or sloshed), they are trapped in a snowstorm there with a nice youngster and share an appreciation for the house once owned by a French emigre of 1792, Boisseguin, and for the Louis XIV furnishings and Poussins. They are further brought together when they read the diaries of a descendant, Algy, born 1875, one of the three boys of a sportsman father with a greater interest in his gun dogs, and a tubercular mother. Algy grows up to be a different kind of sport in call houses. Algy is crushed when his brother appropriates his bird and he kills him in a duel. With the diary's end somewhere around the Great War in which Algy is believed to have lost his life, the snow thaws, and Vincent and Una return to London and the quicker dissolve of strangers in the night who might lose each other in their earlier existences. De Polnay is a casually polished writer who most apparently enjoys the story he tells with the ingratiating independence of spirit it inherits from its participants. So will others, even if you have to call it to their attention.