Plot Summary:William Carnarvon's Midsomer Vinae winery is launching a new sparkling white in the presence of waspish critic Nadia Simons when several guests are poisoned, though not fatally. William's wife Diana tells Barnaby of the opposition to the vineyard by a local group led by nurse Elspeth Rice but Elspeth claims that the vineyard has caused pollution and was indirectly responsible for the death of little Jessica Tyler, killed by a hit and run driver after a wine-tasting. Nadia was a prime suspect and soon afterwards she is killed. The vineyard is in financial trouble and hotelier Lewis Paynton, who is in love with Diana, offers to buy it but he is the next victim. Crime of passion, revenge killing or means of keeping somebody quiet, there is further sabotage and an abduction before Barnaby discovers who committed a vintage murder.
When people start collapsing at the launch tasting of Midsomer Vineyard's newest sparkling wine, Kate discovers that the glasses had been laced with slug pellets. Who could want to sabotage a seemingly innocent wine tasting and why?