English poet Roger Green left the safety of God, country, and whiskey to immerse himself in an austere and sober life on the Greek Island of Hydra. But when Green discovered that his terrace overlooked the garden of sixties balladeer Leonard Cohen, he became obsessed with Cohen's songs, wives, and banana tree. Hydra starts with a poem the author wrote and recited for his fifty-seventh birthday (borrowing the meter of Cohen's "Suzanne," and...