Arriving late at an elegant London dinner party, the narrator of "Tamar," a short story in Mark Helprin's "Ellis Island, and Other Stories," is seated at the "children's table," as a kind of genteel punishment. (The time is close to the start of World War II; the narrator is in London on a mission that fails—raising escape funds for European Jewry.) The teenagers in attendance are new to him and charming—lively, intelligent, dream-ridden. Amused by their chatter, the narrator finds himself under compulsion to entertain. He launches a "long story about Palestine," then races on—his imagination freed—"because they were children, more or less"—to wilder stuff. "I spoke of impossible battles … of feats of endurance which made me reel merely in imagining them, of horses that flew, and golden shafts of light, pillars of fire, miracles here and there … anything which seemed as if...