Music teacher Mrs. Grey claims that she has been deafened by the roar of the jet engines at the airport and intends to sue for damages. Various doctors examine her and,although no physical damage is detected,there is nothing to disprove her allegation. Garnett,however,has his doubts and brings in an old comrade of hers from her days in the wartime Resistance,to catch her off guard.
Didi Druson, a glamorous young film actress,has been receiving threatening calls and messages,telling her that she will not live to see the age of twenty-five. Though he initially dismisses them as a publicity stunt,Garnett nevertheless agrees to fly to Vienna with Didi on the eve of her twenty-fifth birthday to flush out the sender.
A shabby and poorly middle-aged man,suffering from amnesia, arrives at the airport and is identified as being Ian Denning,a wealthy business man who disappeared in the South American jungle some three years earlier. However his wife Jean is adamant that the man is not her husband. Garnett is charged with discovering whether the man is an impostor and,if so,for what reason.
In Germany a general,formerly with the Luftwaffe High Command,has reported a number of planes mysteriously arriving at an air landing strip which has officially been shut down for years. Garnett flies over to meet the general and to discern whether he is imagining things or whether some form of illegal operation is taking place.
in Paris two thieves, Alex and Frenchy,have stolen a large diamond,the Goriot,but it is too big to be safely fenced in France and so they smuggle it into London,where their associate Jenkins will cut it. Garnett suspects that they are up to no good but his doctor,after a routine check,tells him to go home and rest as he is suffering from high blood pressure.