In 1961, Michael Rockefeller, son of then-governor of New York State Nelson A. Rockefeller, mysteriously disappeared off the remote coast of southern New Guinea. Amid the glare of international public interest, the governor, along with his daughter Mary, Michael's twin, set off on a futile search, only to return empty handed and empty hearted. What followed were Mary's twenty-seven-year repression of her grief and an unconscious denial of her twin's death, which haunted her relationships and controlled her life.

In this startlingly frank and moving memoir, Mary R. Morgan struggles...