From the No.1 internationally bestselling author comes the third heart-stopping adventure exploring the incredible history, legends and hidden secrets of Carcassonne and the Languedoc.Set during World War II in the far south of France, CITADEL is a powerful, action-packed mystery that reveals the secrets of the resistance under Nazi occupation. While war blazed in the trenches at the front, back at home a different battle is waged, full of clandestine bravery, treachery and secrets. And as a cell of resistance fighters, codenamed Citadelle, fight for everything they hold dear, their struggle will reveal an older, darker combat being fought in the shadows.Combining the rugged action of LABYRINTH with the haunting mystery of SEPULCHRE, CITADEL is a story of daring and courage, of lives risked for beliefs and of astonishing secrets buried in time.