The first part in a 2 book story - part 2 is Destination New York.
Killed while exercising his love for speed in a racing car, millionaire Sir John Archibald Pump leaves behind ten million dollars (a large sum in those days). It will go to the builders of the first aeroplane to fly from Paris to New York at 1000 kilometres per hour. Jo and Zette's father sets about designing such a plane, but the project comes under threat from a gang of saboteurs led by William and Fred Stockrise, Pump's passed-over nephews, who go to all lengths, from theft to bombing, to prevent it.
(A framed photo of Captain Haddock can be seen hanging on the wall of the Legrand living-room just before Mr Legrand switches on the light to confront intruders.)
