Belphégor

Paris, France,1965. A mysterious masked figure haunted the nights in the Louvre Museum. When a museum guard is found murdered, police commissioner Ménardier is leading the murder case. Fascinated by the gruesome stories about the phantom of the Louvre, called 'Belphégor' by the Parisians, the young journalist André; Belleguarde is to investigate too. One night André even locks himself up in the museum. André; is assisted by Colette Ménardier, the snappy young daughter of the commissioner. Suspicious behavior show the old Lady Hodwin, the alchemist Boris Williams and the attractive though unattainable Laurence Borrell and her lost twin sister Stephanie. André's position becomes more complex when both Colette Ménardier and Laurence Borell appear to be in love with him.

The investigation continues with new appearances by Belphegor. The result is finding secret passages under the Louvre museum.