The secret garden.

THE tent in the garden is about 20 feet by 20 feet. It is large enough to accommodate a long table laden with salad bowls and sandwiches. The twenty or thirty guests, family and neighbors, are nibbling crackers and chatting in small groups. The focus of the gathering is a woman in her early seventies. She looks matronly and vigorous, with unusually blue, mischievous eyes. She offers plates of food and kisses new arrivals and departing guests on the cheek, while a 1-year-old girl clutches at her skirt.

Nothing in the peaceful scene hints at historic distinction or international intrigue. In fact, many of the guests at the party assume it is simply to celebrate some occasion in a local grandmother's life. They would be quite astounded by some of the telegrams in a white envelope lying on a separate table next to the rest of the gifts.

But the telegrams are shown only to family members and a few selected guests by the eldest daughter. One reads, in part: "When you and your husband crossed over to freedom, you began the long process that led to the eventual collapse of the Soviet Union. His revelation helped the West to face up to the reality of Communist subversion and tyranny. Those of us who later fought the battle for freedom to its climax in 1989 and 1991 were greatly in his debt -- and in yours." The telegram is signed Margaret Thatcher.

THE Cold War began during the first week of September 1945, when a young code clerk at the Soviet embassy in Ottawa decided not to return with his family to the Soviet Union. That August, while the atomic bombs exploded over Hiroshima and Nagasaki, Igor Gouzenko had been discussing defection with his wife, Svetlana, in their small Ottawa apartment. Their final decision was prompted by their growing affection for Canada, coupled with a belief that they might not survive their recall to Moscow.

As a cipher clerk Gouzenko knew a great deal about a Soviet spy ring operating through the office of Colonel Zabotin of the GRU (military intelligence). The aim of Zabotin's spy ring was to secure atomic secrets. While being privy to such information might lead to a brilliant career in the Soviet apparat, it might also lead to the Gulag.

Having made his decision, Gouzenko took 109 documents from the Soviet embassy on the evening of September 5 and hid them under his shirt. The same night he went to the editorial offices of the Ottawa Journal, thinking that it would be safer to report his defection to a newspaper than to the police. The puzzled night editors of the Journal turned him away.

For two harrowing days, with a pregnant wife and their 2-year-old son in tow, Gouzenko tried to convince incredulous Canadian journalists and Ministry of Justice officials that he was worthy of a hearing. Having failed, the family sought refuge with a neighbor. By then Soviet agents were breaking down their apartment door. In the end it was this act of the Soviets that prompted a neighbor to call the police.

After five months of debriefing and the hearings of the Kellock - Taschereu Royal Commission of 1946, Gouzenko's 109 documents led directly to the conviction of 11 Canadians and Britons. They included a sitting member of Parliament, Fred Rose, the atomic-energy scientist Allan Nunn May, and the organizing secretary of Canada's Communist Party, Sam Carr. In America Gouzenko's evidence led the FBI to such figures of atomic espionage as Klaus Fuchs, Harry Gold, and the Rosenbergs. Gouzenko's revelations started a process that ended in the collapse of the Soviet empire 45 years later.

The Gouzenkos made a choice and paid a price. Family members left behind in the Soviet Union perished in labor camps. They themselves have led a clandestine existence. To this day Svetlana and her family live under assumed names. For security reasons, the children were told nothing about their backgrounds and were not allowed to learn Russian.

Gouzenko himself did not expect to survive for more than five years. In fact, when he died, in 1982, it was of natural causes. But the Kremlin never forgave his defection. The last known "sleeper" sent to assassinate him was activated after nearly twenty years (he gave himself up instead to the Royal Canadian Mounted Police.)

In the autumn garden under the tent these events seem far away. There is only a great-grandmother with blue, mischievous eyes, and a large family -- perhaps to replace the family lost in camps of Stalin and his successors. They are ordinary Canadians -- teachers, designers, meteorologists -- drinking beer and fruit punch under evergreens planted by a young code clerk forty-odd years ago.

Just a family gathering, except for telegrams in a white envelope. One from the historian and newspaper magnate Conrad Black: "The uniquely important information transmitted 50 years ago and the courage shown by you and your family over a long and difficult period have been an inspiration and a direct benefit to millions of people." Another from William F. Buckley Jr.: "I join with the tens of millions of beneficiaries of your husband's courage in commemorating the fiftieth anniversary of his great, historic exposure." A handwritten note from Nathan (Anatoli) Sharansky: "Those who lived through the oppression of the KGB and the Gulag and survived to be a witness and a participant in the victory over Communism, well understand and remember to whom the world is obliged for starting the struggle toward this victory."

Only Svetlana reads Sharansky's note. There is no point in showing it to family members and guests. It is written in Russian, a language no one else in the garden can understand.