Still on secondment in an EEC counter-fraud organisation in early 1974, Nick & Rosemary Storey are asked to look at a case where wine has been adulterated by diethylene glycol. From their investigations, it appears that the problem is much wider: wine purportedly from one EEC "appellation controlee" being adulterated or replaced by cheap wine from outside the EEC. From working with the Court of Auditors and examining production & export records, they manage to get a large UK supermarket chain to investigate a wine supplier in northern Italy, with Nick and Rosemary accompanying them. But having found where the fraudulent wine is being stored and the damning company records, they have to flee across Italy on stolen motorbikes, escaping by ferry to Corsica. But they still haven't counted on a revenge attack on Rosemary, in which one of their colleagues is complicit.