Gil Petty was once the world's number-one wine critic: a single good review from Petty meant overnight success; a single bad one spelled ruin. Then, during a tasting tour in the little known wine region of Gaillac, Petty went missing. His dead body was found strung upon a cross in the vineyards of southwest France, preserved in red wine and dressed in the ceremonial crimson robes of an ancient society dedicated to promoting Gaillac wine. Petty's murderer was never found, and possible clues in his reviews are locked behind the complicated code he invented to keep them secure prior to publication.

When Enzo Macleod, Scots exile and former forensics expert, reopens this well-chilled case four years later, he finds that the genteel world of winemakers hides a business driven by greed, envy, and desperation, with no shortage of possible killers among the idyllic vines.