[1] It is the first in his series of novels featuring Inspector Joseph French, a Scotland Yard detective of the Golden Age known for his methodical technique.

A robbery of the safe of a diamond merchant in London's Hatton Garden leaves one of the firm's veteran employees dead.

Summoned to handle the case French pursues disparate clues over a number of weeks with some of the trails turning out to be dead ends.

His travels take him from the capital to Southampton and a variety of destinations on the Continent including Amsterdam, the Swiss Alps, Barcelona and Le Havre.

Eventually he believes he has hit on the solution: a former West End actress has adopted an elaborate disguise to carry out the disposal of the diamonds and raise ready cash to flee on a liner heading for South America.