The eccentric owner of a chateau, Lord Wilford, is fond of everything that is connected with criminal cases. His passion takes up so much time that even his secretary hardly has time to see her fiance. When mysterious letters arrive, announcing that a certain Mister X wants to steal a valuable statuette, the Lord is very enthusiastic. Apparently he himself will now experience a real criminal case! His secretary persuades him to hire a famous detective from London - none other than her fiance. But he is far from being a talented detective, and when a valuable pearl necklace disappears, the fiance falls under suspicion to be the thief.