Back in Frederick, Lisa Olson confronted Vincent Ruwet, her father's old boss at Detrick. He had regularly visited Alice Olson, shared a drink with her, become a trusted friend of the children. Ruwet stalled at first but eventually confirmed that the man in the story was Frank Olson and that he had known the details in The Post story all along.

If Ruwet had known all along, then the family had lived for 22 years in a community of lies: families of government scientists who had kept the truth away from a family dying from the lack of it. This culture of secrecy had also contaminated the family from within. Alice Olson covered the whole subject of Frank's death with a silence that was both baffling and intimidating. Her mantra, whenever Eric would ask what really happened in Room 1018A, was, ''You are never going to know what happened in that room.''

Maintaining stoic silence took its toll. By the 1960's, Alice Olson was routinely drinking on the quiet, locking herself in the bathroom and then coming out mean and confused. One time, when Eric returned from a year away in India, he walked right past her in the airport. The drinking had left her so thin and wasted that he didn't recognize her. All the time, Ruwet had been there for her, keeping her company. It later turned out that he had received orders from the C.I.A.'s director, Allen Dulles, to keep in touch with her.

With their mother locked in silence, the children were left alone with their own sense of shame about their father's death. Eric told other children that his father had suffered ''a fatal nervous breakdown,'' without knowing what that could possibly mean. Thanks to The Post's revelations, the summer of 1975 was the family's ''Copernican Revolution.'' They gave the exclusive on their personal story to Seymour Hersh of The New York Times, and when he came through the door of the house in Frederick, his first words were: ''This must be the most uncurious family in the United States. I can't believe you fell for that story for 22 years.'' Later, at a news conference in the backyard at Frederick, under the big trees, the family announced that they were going to sue the government for wrongful death. Their ultimate purpose, they said, was to imprint what had happened to their father in ''American memory.''

The news conference had immediate results. On July 21, 1975, Alice, Eric, Nils, Lisa and Lisa's husband, Greg Hayward, were invited to the White House. In the Oval Office, according to newspaper accounts, President Gerald Ford expressed ''the sympathy of the American people and apologized on behalf of the U.S. government.'' There is a photograph of Alice shaking the president's hand. Her face is glowing. Even so, catharsis was brief. The meeting with the president lasted 17 minutes.

A week or so later, Eric, Lisa, Nils and two lawyers met the C.I.A.'s director, William Colby, at the agency's headquarters in Langley, Va. In his memoirs, Colby remembered the lunch as ''one of the most difficult assignments I have ever had.'' At the end of the lunch, Colby handed the family an inch-thick sheaf of declassified documents relating to Frank Olson's death. What Colby did not tell them -- did not reveal until he published his memoirs just three years later -- was that Frank Olson had not been a civilian employee of the Department of the Army. He had been a C.I.A. employee working at Fort Detrick.

The Colby documents were photocopies of the agency's own in-house investigation of Olson's death and like Eric's collages: a redacted jumble of fragments, full of unexplained terms like the ''Artichoke'' and ''Bluebird'' projects. These turned out to be the precursors of what became known as MK-ULTRA, a C.I.A. project, beginning in the Korean War, to explore the use of drugs like LSD as truth serums, as well as botulism and anthrax, for use in covert assassination.