Belgian detective Hercule Poirot is called to France after receiving a distressing letter with an urgent cry for help. When he arrived Merlinville-sur-Mer Researchers found that the man who wrote the letter, Monsieur Renauld, a South American billionaire, was stabbed to death and his body was thrown into a newly dug grave in a golf course adjacent to the residence.
Meanwhile, the rich man's wife was found bound and gagged in her room. It was evident that Seo der and his wife were the victims of a failure to invade, resulting in Cieor kidnapped and killed.
There were no suspects for his wife who had a dagger as a weapon. His bitter son, who must be killed for independence And his mistress, who refused to be ignored - and felt deserved the fortune of the deceased.
The police think the culprit has been found. But Poirot had his doubts.
Why does the deceased wear a coat that is too large for him?
And a love letter that does not get attention in anyone's pocket?
Before Poirot was able to answer these questions, the case was upside down by a second, murdered body was found.