The Murder on the Links
'An urgent appeal for help brings Hercule Poirot to France where he finds he has arrived too late. His client, a mysterious millionaire, has been brutally stabbed to death...the corpse flung carelessly into an open grave.
But Poirot knows all is not as it seems. He starts to unravel the strange circumstances surrounding this baffling murder, and discovers that the clue to the killer's identity lies in a crime committed more than twenty years in the past.'
The shallow grave where the victim was found was on a golf course that was being built, which links with the location of this cache.
The cache is on the approach to the golf course and is accesible at all times.