Plague Victims Catapulted over Walls into Besieged City   Early germ warfare.  The dead hurled this way turn like wheels in the sky.  Look: there goes Larry the Shoemaker, barefoot, over the wall, and Mary Sausage Stuffer, see how she flies, and the Hatter twins, both at once, soar over the parapet, little Tommy’s elbow bent as if in a salute and his sister, Mathilde, she follows him, arms outstretched, through the air just as she did on earth   Of all the pleasures poetry can give, one of the greatest has to be the aha! flash: an explosion in the brain that makes the world more understandable, mysterious, poignant, piquant, enjoyable—that lets us see ourselves and other people with new eyes, and routs…