A retired tea-broker with a passion for fine claret looks forward to his annual autumn tour of the Bordeaux vineyards. But a chance conversation in a London drawing-room plunges him into strange happenings. A young American woman begs him to watch over her friend, the heiress of a rose-pink ch teau above the river, who has broken off her engagement without explanation. The young woman swears that every letter from the ch teau reveals shifting, half-formed faces beneath the ink.
Reluctantly drawn into the affair, the traveller arrives for the wine-vintage celebrations to find a small, uneasy party and a celebrated French detective on holiday nearby. As strange warnings multiply, the brittle opal of the ordinary world begins to crack, and a dark, occult-tinged conspiracy emerges from the shadows of the France's wine country.