When Lilian Shang, born and raised in America, discovers her father’s diary after the death of her parents, she is shocked by the secrets it contains. She knew that her father, Gary, convicted decades ago of being a mole in the CIA, was the most important Chinese spy ever caught. But his diary, an astonishing chronicle of his journey as a Communist intelligence agent, reveals the pain and longing that his double life entailed — and it points to a hidden second family that he’d left behind in China.