The story takes place in 1915, WWI has just started, Arsene Lupin returns as war veteran Don Luis Perenna. He is called to uncover the details of the mysterious murder of a Moroccan man, Essares Bey, the disappearance of 300 Million Francs in Gold, and the connection between another war veteran, Captain Patrice Beval and a volunteer nurse working in a military hospital in Paris, affectionately known as Mother Coralie. But their lives are in danger, and Arsene takes it upon himself to play detective and find the culprit, and more importantly, the gold! Lupin is smarter, stronger, wittier, more invulnerable than ever. Will he be able to derail the dastardly plan before it unfolds?