<p> Hercule Poirot stood on the clifftop. Here, many years earlier, there had been a fatal accident. This was followed by the grisly discovery of two bodies?a husband and wife who had been shot dead. </p> <p> But who had killed whom? Was it a suicide pact? A crime of passion? Or cold-blooded murder? Poirot delves into the past and discovers that ?old sins leave long shadows.? </p>