Allmen and the Mystery of the Dahlias

Original title: Allmen und das Geheimnis der Dahlien

Ironically, the art detective Johann Friedrich von Allmen is staying in a high-end Zurich hotel when a million-dollar dahlia painting disappears from the private suite of the owner. What would be more obvious to the eccentric Dahlia Gutbauer than to entrust "Allmen International Inquiries" with the discreet replacement?