The Mystery of the Crown Jewels (1916)

On his way home from a business trip, the young detective Karl Frank meets the siblings Kuno and Margit von Krall. Immediately captivated by Margit’s beauty, Frank accepts an invitation to visit them at their hotel soon. That same evening, he is hired for an important mission: he must prevent a burglary at the city’s jeweller. However, he fails miserably as the mysterious masked thief escapes. He retires to the country estate of his new friends to nurse his wounded pride, still unaware that he will soon become part of a shady business. (Stumfilm.dk)