The Seret of Sarek (L'Île aux trente cercueils / The Island of Thirty Coffins) is a french novel by Maurice Leblanc, 1919.
The action begins in France in 1917. The heroine of the story is Véronique d'Hergemont. Fourteen years ago, in 1903, her father, Professor Antoine d'Hergemont, kidnapped her baby and received the news that the two had drowned in the sea. It was her father's revenge on Véronique's marriage to Count Vorski. While watching a film, Véronique spots her childhood signature ”V d'H” mysteriously written on the side of a hut in the background of a scene. Her visit to the location of the film shoot deepens the mystery, but also provides further clues that point her towards long-lost relations and a great secret from ancient history: She finds a prophecy: ”Four women on the cross, stone of God that gives life or death. Thirty sacrifices for thirty coffins”. When Véronique arrives on the island of Sarek, the prophecy comes true. Many people die horrific deaths and Véronique also ends up in a torture chamber. She faces the sinister forces. It's a secret that will require the services of a particular man to unravel.