The owner of a copy of a work by Claude Monet is murdered, and the picture stolen, but it seems strange to kill someone over a simple copy; the investigation leads Antoine and Florence on the trail of a particularly talented copyist.

Antoine and Florence are on the trail of a talented copyist of Claude Monet's work.

A mysterious contact draws Antoine and Florence into a macabre parody of a treasure hunt, based around a work by the artist Gustave Courbet: as each riddle is solved, a body is discovered.

The murderer inspired by Gustave Courbet seems determined to follow his Machiavellian plan right to the end; one question remains: why he appears to address himself directly to Antoine.

A seminarian is stabbed to death, and a tattoo on the victim's chest intrigues Antoine and Florence.

The seminarian's murder is not the first crime associated with the lost Hieronymus Bosch painting.