Sir Stafford Nye's flight home from Malaya takes an unexpected twist, when a woman approaches him in the Frankfurt Airport. The woman claims that her life is in danger, and that she needs his help. Nye agrees to lend her his travelling cloak, passport, and boarding ticket. A colleague in London, Horsham of Security, tells Nye that his action in Frankfurt saved Mary Ann's life; Sir Stafford heard another name announced for her at the airport, Daphne Theodofanous. Nye has dinner with his friend Eric, worried for his professional reputation. Mary Ann returns his passport, taped into a magazine in his post. Nye advertises in the personals section of the newspaper for his mystery woman, signing himself as Passenger to Frankfurt. She replies with tickets to an opera, given at a discreet meeting on a bridge. His great-aunt Matilda hints to him of a terrible world-wide conspiracy, which uses a phrase of music from Richard Wagner, related to the opera "Siegfried" (1876). Matilda detects that he has a woman in his life now.