A Swiss bank discovers that the confidentiality of several anonymous numbered accounts has been compromised and that blackmail threats have been made to five of the account holders. Among the targets is a crooked arms dealer who receives a demand for five million Swiss francs; when he refuses to pay, he is shot dead. The blackmailer then insists that the bank itself pay ten million francs to preserve the secrecy of the accounts.
To uncover who is behind the scheme, the bank hires David Christopher, a former U.S. Justice Department official now living in Geneva, to lead the investigation. Christopher sits down with the four surviving blackmailed clients—Denise Abbott, a striking Zürich resident; Dwight McGowan, a Texas businessman; Robert Hayes, a Chicago crook; and Korsak, a Dutchman—asking pointed questions about their finances and their connections to anyone who might profit from exposing the accounts.
As the inquiry unfolds, a slate of suspects emerges. One key figure is Rita Jensen, the mistress of the bank’s vice-president, Franz Benninger; there is also Franz Benninger himself, who seems to wield influence behind the scenes. Completing the list are Kosta and Sando, both involved in the shadowy world of crime and intent on eliminating Hayes and Christopher to protect their interests.
Bank president Johann Hurtil is reluctant to accept that his associate Benninger could be corrupt, yet the investigation reveals troubling evidence. It turns out that Benninger transferred control of a bank account to his mistress—a move that was legitimate in name but thwarted by missing or improper documents, a detail that casts serious doubt on his integrity. Throughout the case, Captain Hans Frey of the Swiss Federal Police keeps a close eye on Christopher, suspicious of the American’s aggressive pursuit and his willingness to bend rules to crack the case.
Faced with mounting pressure, the bank makes a dramatic move: they decide to pay the blackmailer using uncut diamonds. Christopher insists on escorting the precious stones to the collection point, which sits high in the snow-clad Alps. The tension tightens as the operation unfolds, revealing that the supposed blackmailers are, in fact, turning the scheme against one another. The diamond collector is shot, plummeting from a perilous alpine rock face, and in the aftermath, Christopher manages to recover the stones.
Across the icy peaks and through the labyrinth of loyalties and lies, the investigation threads together a web of ambition, deceit, and risk. The story tracks how individuals connected to the bank—whether through power, money, or romantic entanglements—become entangled in a plot where trust is scarce and every move could be fatal. In the end, the pursuit of truth hinges on Christopher’s steady persistence in a case where the motives of the players are as shifting as the alpine weather, and the diamonds themselves symbolize a fragile resolution in a crisis rooted in secrecy and greed.
