See Delphi And Die, Белый

The ancient sports of murder and myth
Stunned by a dramatic appeal from his otherwise cool mother-in-law, Falco cannot resist. His brother-in-law has been diverted from his route to Athens University by a man whose newly married daughter disappeared, with her husband, while visiting the Olympic Games as part of an extended wedding trip. Suspecting a classic cover-up, Aulus enrols Falco's help in solving the case. And of course his mother-in-law hopes to hurry her son along to university by passing the case over to Falco.
Joining the rest of the married couple's tour group on the remains of their Grand Tour, Falco and Helena seize the opportunity to interview the owner/manager of 'Seven Sights Travel', as well as the other guests.
Seemingly not getting very far, they can at least make the most of the splendid sights; but finally, on reaching Delphi, Falco and Helena unravel the mystery of the bride and groom...