Themes

The overarching theme of The Murder of Roger Ackroyd and The Moving Finger is the same as that for all crime fiction: the clash between good and evil. The working out of this theme on the side of good constitutes the essentially comic nature of such fiction.

Within this theme Christie develops two others in her books. In the Hercule Poirot stories, readers are constantly reminded of the importance of thinking and of order. Poirot eschews the Holmesian technique of getting down on his knees with a magnifying glass to find clues; instead, he uses his "little grey cells" to solve the mystery, often making gentle fun of the other characters for their desire for action rather than thought. Poirot also seeks logic and order above all, even to the habit of straightening pictures, pencils, or other objects, as well as the clues in a case. This passion...