In 1915, in the middle of the First World War, Gabriel Ferraud, a soldier of the French army, was wounded on the front. Rescued and evacuated, he was approached by army officials. He learns that he is selected to integrate an ultra-secret research project: the Sentinels program...

Gabriel's wife, Irene, decides to investigate the cause of her husband's death. Captured by the French, Gruber, a German spy, is interrogated about the enemy program. Deployed on a mission, the Sentinels discover the work of a German soldier with formidable abilities.