The Channel Tunnel is all very well as a mundane means of crossing La Manche but there are those who still believe in airships as the luxury transport of the future. In a rare spirit of entente cordiale, the governments of France and Britain agree to a trial run, and plan a grand inaugural flight involving their heads of state. But - quelle horreur! - the organisers have overlooked the most important part of every French occasion - the food and the wine. Honour is at stake and a desperate call for help goes out to Le Guide, France's most distinguished gastronomic publication. Monsieur Pamplemousse, ex Surete sleuth turned food inspector, is called on to rectify matters.The assignment gets off to an inauspicious start. As he nears the launch site in Brittany, Monsieur Pamplemousse's 2CV is run off the road by a carful of decidedly ungodly nuns. And the lady trapeze artist who rescues him clearly has something other than the evening's acrobatics preying on her mind. When an old friend cuts him dead, he suspects the worst...