In a general sense, The French Powder Mystery is primarily concerned with good and evil. Evil, in the form of narcotics and murder, has intruded into the self-contained world of the French family and business. As in other formula literature, such as the fairy tale and the western, good and evil are painted with broad strokes in the detective story. The French Powder Mystery is no exception to this pattern.
Characters are not allowed complex emotions or motives for their behavior.
They either uphold the rules of decency and goodness, or they do not.
The appeal of this black-and-white presentation of virtue and vice rests upon shared assumptions of author and reader about good and evil. The typical reader desires that those who are honest, faithful to friends and family, and hard-working will be rewarded, and that those who are dishonest, disloyal, and lacking in industry will be punished...