Alexandra Fuller is a white woman, born in England but raised in Africa. Her first memoir, the bestselling Don't Let's Go to the Dogs Tonight, told how her family came to live in Rhodesia (now Zimbabwe) in the early 1970s and experienced the civil war that resulted in the overthrow of the whites-only government and installation of black majority rule.

After the war, Fuller's parents and older sister settled in Zambia while Fuller married an American and moved to Wyoming as a compromise with her husband. But every so often she returns to her parents' fish farm on the Pepani River—a place unequipped with plumbing or walls.

A Christmas visit a few years ago inspired the trek that is the subject of her second memoir, Scribbling the Cat. Over drinks at Chongwe Lodge, a village bar, talk turns to man identified only as "K," a white veteran of the Rhodesian civil war known for being "a tough bugger," "a violent enough teetotaler," and a "bloody good fighter." Intrigued—and ignoring her father's reminder that "curiosity scribbled the cat" (an African variant of the proverbial warning)—Fuller drops in on K at his banana farm.

K is a lion of a man, tattooed and work-worn. "He looked bullet-proof," Fuller writes. "And he looked as if he were here on purpose, which is a difficult trick to pull off in this wooly climate. He looked as if he were his own self-sufficient, debt-free little nation … as if he owned the ground beneath his feet, and as if the sky balanced with ease on his shoulders. He looked cathedral."

Fuller proposes a journey to K's old battlefields, through Zambia to Zimbabwe and Mozambique. On the way, he confronts his ghosts and she chronicles his stories—including the childhood experiences that profoundly shaped him. Ostracized, ...