Agent Alan Curtis of the Western Intelligence Liaison (W.I.L.) uses blackmail to enlist five people to help him stop revolutionary exile Alexandre Diakim from returning to his home country. Those blackmailed are a French-Algerian assassin named Melissa Lascade; a former follower of Diakim, now a journalist, American Scott E. Allison; an eight-year-old French boy named François Diderot; British foreign officer Charles Lord, whose homosexual affairs threaten his career; and Diakim’s former lover, Katina Petersen, an American expatriate living in Milan, Italy. However, they are all unaware of each other’s involvement. Curtis gathers the five in Gmunden, Austria, where Diakim is plotting his homecoming. Under Curtis's instruction, Scott arranges a meeting with Diakim to convince him to delay his return home until the timing is right. Against the wishes of his advisors, Diakim meets with Scott but insists there is no W.I.L., accuses Scott of being a Central Intelligence Agency (C.I.A.) operative, and dismisses his warnings. Later, Curtis offers Scott a plane ticket to return to the U.S., but the reporter remains in Gmunden to cover the story. When Katina summons Curtis to her hotel because she wants to go home to Milan, Curtis informs her that he has also brought her son François, to Austria. Impregnated by Diakim, Katina gave birth to the boy without Diakim’s knowledge. Curtis is using Francois to force Katina to speak with Diakim. Meanwhile, Scott monitors Curtis's movements. The assassin, Melissa asks Curtis when she is to kill Diakim, and he replies that he does not know, perhaps never. Scott witnesses Melissa taking target practice and deduces the reason for her presence. Later, Diakim greets Katina warmly, but does not believe the letter she recently sent explaining François’ birth. Diakim assumes Curtis invented the story, but Katina confirms the truth, admitting that she should have had an abortion. When Diakim slaps Katina, she muses that he is acting just like old times. Elsewhere, Curtis phones his wife, who believes him to be a gentleman farmer negotiating agricultural rates. One night, Scott follows Britsh officer Lord and Curtis's man, Jennings, to a wine bar and plants a note in Lord’s coat. The following day, Katina informs Curtis that neither she nor Diakim is going to go along with the agent’s plan. However, Curtis has arranged for Diakim to see François during a boat ride on a lake, hoping that it will inspire the revolutionary to remain in Austria. Lord meets Scott in a church confessional and tells the reporter that he once arranged a loan for Diakim’s organization, which has never been repaid. Scott reveals that Melissa will kill Diakim if they fail to convince him to stay. Meanwhile, on the boat, Curtis attempts to convince Diakim himself, urging the revolutionary to take Katina and François somewhere safe. Curtis later authorizes Lord to cancel Diakim’s debt and offer him $500,000. However, Lord and Scott plot to foil Curtis's plan by using the $500,000 to pay Melissa to stop her from killing Diakim. Contradicting Curtis, Scott tries to convince Diakim to return to his country. Meanwhile, Lord convinces Melissa that Curtis is untrustworthy and offers her the money to not kill Diakim. The next day, Scott sneaks in to Katina’s hotel and convinces her to help him and Lord. Unaware of the conspiracy, Curtis takes Lord and the $500,000 to Diakim, insisting that Lord and the revolutionary sign a receipt. Although Diakim refuses the money, Lord forges his signature, unbeknown to Curtis, then drops the briefcase full of cash into a ravine, where Scott is waiting. Handing over the fraudulent receipt to Curtis, Lord leaps from Curtis's moving vehicle and attempts to escape on foot. Curtis and his driver, Brewer, give chase. Brewer shoots Lord and they take him back to W.I.L. headquarters. Meanwhile, Scott and Katina meet Melissa on a boat and give her the briefcase. When the boat reaches the other side of the lake, Melissa disembarks, followed by one of Curtis's men. Elsewhere, Diakim telephones a member of the press to announce that he will be flying home that night. Back at W.I.L. headquarters, Lord dies and Curtis orders his operatives to shut down the office as news of Diakim’s departure spreads. Discovering the plot, Curtis demands his money from Melissa. When she balks, he threatens to rescind the release of her jailed boyfriend. Acquiescing, Melissa hands over the key to a bus station locker, where she placed the money. Later, Diakim and his entourage arrive at the Vienna airport for a press conference as Curtis, his men, and Melissa establish a position from which she can shoot the revolutionary. Scott and Katina attempt to enter the press conference, but are rebuffed, and Curtis chastises them for their idealism. Curtis's men arrange to switch Diakim’s briefcase with one of their own filled with explosives. A member of Diakim’s team recognizes Katina and lets her and Scott into the press conference. Scott grabs the microphone to announce that there will be an assassination attempt on Diakim at the airport, and Alan Curtis is responsible. As Diakim moves through the airport surrounded by his followers, Melissa tells Curtis it is impossible to fire a shot. A security guard stops Katina and Scott at the gate and they bid Diakim farewell. Meanwhile, Melissa attempts to flee and is captured by Curtis's men. Just before Diakim reaches the plane, Curtis detonates a bomb in the briefcase and Diakim and those around him are killed. In the bedlam that follows, Scott pleads with Katina to help him spread Diakim’s legacy. As Scott dictates his story into a tape recorder, he begins to cry. Melissa tells Curtis that she always knew about the plotted assassination and Curtis leaves. As Melissa walks away, one of the men kills her, then places the detonator beside her body, using her as the decoy assassination.