Doctor Gachet's portrait

A picture named «Doctor Gachet's portrait» has been stolen a night from a museum. Immediately, the news offer the event and our heroes start the research after some clue that leads them to the thief. After travelling across some countries following his trace, they realize that a smuggling network is behind the robbery, led by minister Goring. Among their loot is an enormous amount of pictures stolen from private collectors, with the aim of transporting and hiding them beyond their frontiers.