“The Tree of Gisors” is a novel about the Templar Jean de Gisors and the great secret of his family estate, about the history of the Templar Order in the 12th century, about the Albigensian heretics and their satanic rites, about the Second and Third Crusades, about the illustrious and memorable king Richard the Lionheart and his dissolute mother Eleanor of Aquitaine, about the famous French troubadours and how the Crusaders lost the Holy Land.