Prolific British author Gardner, in the introduction to his predictable fourth Suzie Mountford mystery (after 2004's Angels Dining at the Ritz
), makes no apology for hanging his tale on a premise at least four other novelists have used before—the Nazis' efforts to learn the British secret plans for invading Normandy. Mountford, a "Woman Detective Sergeant," becomes involved in espionage when her investigation into the torture-murder of a colonel reveals that the victim was part of the inner circle of military strategists. She's drafted into the ranks of British intelligence, which complicates her tense relationship with her lover and superior, Supt. Tommy Livermore. None of the characters is especially memorable, while Mountford's usual competence and self-sufficiency is again undercut by her role toward the end as a damsel in distress. (Feb.)