When the sales figure of one million and a half copies of Dinner at Antoine's confronts one, it is impossible to say that Frances Parkinson Keyes had better not think of herself as a writer of suspense. Let's concede this will sell. The full battery of promotion stands behind it, and the avid interest of her loyal cohorts. But for this reader the story here told falls far below such of her books as Steamboat Gothic, Joy Street- or to go back- Crescent Carnival; the characters are cardboard figures; the resolution of the mystery artificial and not growing out of the development either of incident or character. However, the accepted Keyes' techniques are here once more,- a setting of London's diplomatic circles, with an impoverished but still somewhat glamorous scion of England's nobility as a dea ex machina; a group of characters brought together at the entertainment provided for a visiting ambassador whose somewhat seamy past reaches out to include Lady Laura herself, the beautiful -- and good- leading lady of a current hit, and the mysterious Ambassador from the Middle East country to which the visiting ambassador and his flamboyant bride are assigned. Then Baldwin Castle, guest of honor, is murdered, and almost everyone among the guests at the select entertainment provided by the American charge d-affaires is suspect:- the means and the opportunity are there; cherchez the motive. In the search, many stories are unfolded, and it is a disappointment- to this reader- when the murderer proves to be only remotely involved, and the murder purely fortuitous. An exotic tale, the plot spun with due suspense and skill. It will sell- and rent.