Following the London tragedy, there is a ceremony scheduled to promote peace and healing. Arsène Lupin plans to commemorate Cardia Beckford's accomplished ambitions with a unique gathering. Yet, while seeking a suitable present, Lupin becomes caught up in a heist centered on a valuable diamond. He's captured and charged with the offense, prompting his accomplices, Cardia, and an unexpected comrade to clear his name and reveal the genuine perpetrators behind the theft.