Three thefts are simultaneously investigated in three cities, but these apparently isolated crimes have much more in common than anyone imagines. In Rome, the police enlist the help of renowned art investigator Gabriel Coffin when tracking down the stolen masterpiece. In Paris, Genevi - ve Delacloche is aided by Police Inspector Jean-Jacques Bizot, who finds a trail of bizarre clues and puzzles that leads him ever deeper into a baffling conspiracy. In London, Inspector Harry Wickenden of Scotland Yard oversees the museum's attempts to ransom back its stolen painting, only to have the masterpiece's recovery deepen the mystery even further.