The Canadian Caper was the unofficial name given to the covert rescue by the Government of Canada of six American diplomats who evaded capture during the seizure of the United States embassy in Tehran, Iran, by Iranian students on November 4, 1979, precipitating the Iran Hostage Crisis. . . .The operation itself was initiated at great personal risk by then Canadian ambassador to Iran, Ken Taylor, and Canadian Immigration officer John Sheardown who provided sanctuary for the six endangered American diplomats in their own private residences. Two “friendly-country” embassy officials assisted as well, and an unoccupied diplomatic residence was used for several weeks.
Ambassador Taylor contacted then Canadian Secretary of State for External Affairs, Flora MacDonald and Canadian Prime Minister Joe Clark for assistance, who expressed support for the effort. The decision was made to smuggle the six Americans out of Iran on an international flight using Canadian passports. To achieve this, Canada's Parliament convened its first secret session since World War II to grant permission for an Order-in-Council to be made for the issuance of Canadian passports to the American diplomats in Canadian sanctuary. The granted passports, feigning Canadian citizenship and a set of forged Iranian visas prepared by the U.S. Central Intelligence Agency would be used to attempt an escape from Iran.
The CIA enlisted its disguise and exfiltration expert, Tony Mendez, to provide a cover story, documents, and appropriate clothing and materials to change their appearance. Mendez worked closely with Canadian government staff in Ottawa, sending as much as he could in the diplomatic pouch, before flying to Tehran with an associate to assist with the rescue. There were alternate passports and identities for a variety of scenarios, but the cover story selected had the six being a Hollywood crew scouting movie locations. The elaborate back-story involved a film named Argo, for a Middle-Eastern feel, and a post office box in Los Angeles for “Studio Six”, backed by display ads. (The movie scenario was considered one way to get an armed team into Tehran to retake the embassy.) . . .
You can hear an interview with Mr. Mendez here. It's well worth the listen.