A team of spies tries to recover a CIA letter that could trigger an international incident.

An American intelligence officer signs an agreement with the Soviet Union stating that both countries will attack China, and the U. S. government hastily assembles a group of espionage agents to recover the unauthorized treaty called the "Kremlin Letter." The team, under the leadership of The Highwayman, consists of Rone, a retired U. S. Navy officer; B. A., a safecracker's daughter who replaces her ailing father on the mission; Janis, a small-time pimp from a Mexican brothel; The Warlock, a transvestite found in a San Francisco gay bar; and Ward, The Highwayman's top assistant. In New York, the Americans have a lesbian seduce the daughter of U. S.-based Russian spy Potkin in order to blackmail him into turning over his Moscow apartment as a base for their operations. In Moscow, they bug the residence of Secret Police Chief Kosnov, who is married to Erika, the widow of an enemy spy; Kosnov is currently engaged in a power struggle with political leader Aleksei Bresnavitch. Meanwhile, B. A., who has become Rone's lover, is captured by Bresnavitch. When Ward temporarily leaves the country, Potkin confesses to Bresnavitch what has happened. Bresnavitch has another problem, however: Rone has discovered that he (Bresnavitch) is a traitor and that the Kremlin Letter is in Peking. Ward is also revealed to be a traitor, working for Bresnavitch. Upon his return, Ward kills Erika, who had devised a plan to sneak Rone out of Russia, and at the airport, he also murders Kosnov, an old friend who had doublecrossed him several years before. By now Rone is ready to retire, but Ward will release B. A. only if Rone will return to the United States for one more mission--to murder Potkin's wife and daughter.