Paul Temple and the Harkdale Robbery — Francis Durbridge

The bank robbers were caught straight away, but in the bag there was a 'Concise Oxford Dictionary' instead of money. Moreover, in Paul Temple's garage was the body of one of the robbers. So commences one of the strangest cases of Paul temple's career. Before it is done he comes face to face with deeply hidden underworld figures, including the 'Master Mind'.