Sixteen stories in which the sleuthing is shared by the author's longtime hero, Detective Inspector C.D. Sloan, of Calleshire county (A Dead Liberty, 1987, etc.), and well-connected Henry Tyler, of the Foreign Office. In ``A Fair Cop,'' one of the shortest and liveliest of the pieces here, Sloan finds an ingenious way to jail a villain who, through no fault of his own, has failed to commit the crime he set out to do. In ``One Under the Eight,'' however, Sloan's solution to a locked-door puzzle will be mostly incomprehensible to all but the computer savvy. Henry Tyler, in ``Cause and Effects,'' manages to ferret out the highly unlikely means by which a country doctor poisons his wife in the middle of a dinner party. And Sloan, serving extradition papers on Englishwoman Laura Vercollas, suspected of murdering her husband, engages Laura in some astute questioning and turns up answers that will probably set her free (``Home is the Hunter''). Neither protagonist is involved in ``The Misjudgment of Paris,'' a story about an executive's major promotion that's told with simplicity and charmrare qualities in this collection of self-consciously clever tales, too often stuffed with literary references and dull asides. From respected veteran Aird, uncompelling work in an unsympathetic format.