This 1944 mystery begins with a group of criminologists discussing murder cases, one remarks that murder mysteries are written backwards, beginning with the crime when in fact, the real story begins much earlier.
The action then shifts to other characters as the countdown to zero hour begins. The diverse group includes a would be suicide; an athletic young man and his current and former wives; a planter from the Far East; and a wealthy invalid and her impoverished companion. We see these characters and others take the steps that ultimately lead then to an isolated seacoast estate and murder.
This is a Sgt. Battle mystery (The Seven Dials) and we are treated to some background information on him. Poirot is mentioned but only in passing. Christie, speaking through Battle, makes clear her feelings about the then current fad of psychology and those who attempt to apply it while only half understanding the theories.
The 60 year old story has worn well overall. A 21st century reader would be puzzled only by the stigma that some of the characters applied to divorce and the relatively unsophisicated forensic proceedures. This is, as is typical of Christie's work, well plotted, the clues are all there for the reader to follow through the maze of red herrings but nearly impossible to solve before the detective.