A charming and very daring thief known as Arsene Lupin is terrorizing the wealthy of Paris. He even goes so far as to threaten the Mona Lisa. But the police, led by the great Guerchard, think they know Arsene Lupin's identity, and they have a secret weapon to catch him.
Mary Turner gets a three year prison sentence for a crime she didn't commit. Once released, she plots to get back at the man responsible for her conviction.
Although his murdered friend was by all accounts a scoundrel, Edward Wales is determined to trap his killer by staging a seance using a famous medium. Many of the 13 seance participants had a reason and a means to kill, and one of them uses the cover of darkness to kill again. When someone close to the medium is suspected she turns detective, in the hope of uncovering the true murderer.
