The adventures of the time-travelling Butterfly Club continue . . . When the Butterfly Club asks the time thieves to go to Paris and steal a little-known painting known as the Mona Lisa, Aidan can only think of one man who can make things disappear - Harry Houdini. The three children and Houdini travel to 1911 Paris where they face their most difficult mission yet. To add to the challenge they soon discover they are not the only ones planning to steal the Mona Lisa. A group of artists also seem intent on stealing the portrait, as it contains hidden clues to a much greater treasure, clues that were placed there in Renaissance times by the Mona Lisa's creator Leonardo Da Vinci himself.