"Eine Leiche für Perrot" von C'rysta Winter

The Setting

Achille Perrot, grandson of the great Hercule Poirot is staying in Germany. Pour les vacances. An excellent opportunity to pay his friend, Inspector Jeff, a visit in Lower Saxony. But already on the second day of his idyllic sojourn in the Soltinger Heath, things take a bad turn. The ravishing bride, Lady Lucy Atterberry, is found dead on the banks of Lake Weidenhof. None of the British noble wedding guests appear to have noticed anything at all. Achille Perrot and Inspector Jeff are literally fishing for clues.

To make matters worse, a playing card turns up during the investigations—the card of death.
Soon after, four elderly ladies vanish. It is exceedingly fortunate that Achille Perrot has not only inherited his ancestor’s predilection for moustaches but also his excellent sleuthing gene.