Nicholai Hel, born in the ravages of World War I China to an aristocratic Russian mother and a mysterious German father, raised in the spiritual gardens of a Japanese Go Master, survives the destruction of Hiroshima to emerge as the world’s most artful lover — and its most accomplished and highly paid assassin. Genius, mystic, master of language and culture, Hel’s secret is his determination to attain a rare kind of personal excellence, a state...