Peter Buck Feller's father disappeared in Moscow in 1938, when Feller was just six months old. As a young boy he asked his mother about him, but his questions invariably went unanswered.

Decades later, after the collapse of the Soviet Union, Feller embarked on a detailed search to reclaim his father. It took him and his adult daughters to Moscow, Siberia, and Germany. He gained access to a now-declassified espionage FBI file, which contained an anonymous letter from a man who had been imprisoned in one of Stalin's gulags: "I plan to write a book about all what occurred to me during these dreadful ten years. The title of this book, I would like it to be ‘The Last Gasp of William Schwarzfeller’."

Feller was stunned. William Schwarzfeller was his lost father, for whom he searched, in one way or another, all of his life. He learned that his father had been an agent for Red Army Intelligence. He was arrested in 1938 and starved to death in a gulag in 1943. This new information led him to a host of discoveries, his mother's vast FBI file, and a story about his father on the front page of the Communist newspaper The Daily Worker.