Renée Fleming stars as Rossini’s sorceress, opposite no fewer than six tenors. Mary Zimmerman returns to direct, bringing her fine-tuned theatricality to a work she describes as “a buried treasure, a box of jewels.” The fanciful story of the sorceress who enthralls men in her island prison of sensual delights, Zimmerman says, “has an epic, enchanted quality and a tremendous visual element.”