Hercule Poirot stood on the cliff-top. For here, many years earlier, there had been a tragic accident – the broken body of a woman was discovered on the rocks at the foot of the cliff. This was followed by the grisly discovery of two more bodies – a husband and wife – shot dead. But who had killed whom? Was it a suicide pact? A crime of passion? Or cold-blooded murder? Poirot delves back into a crime committed 15 years earlier and discovers that, when there is a distinct lack of physical evidence, it’s just as well that ‘old sins leave long shadows.'

This story is part of Agatha Christie’s murder in retrospect series, a collection of stories which look at a crime several years after the fact, piecing together testimonials and witness reports to finally uncover the truth. This time we see Mrs Oliver’s goddaughter, attempting to find out the truth about her deceased parents – who killed whom?