Since the time of ancient Rome, science has explained many phenomena, including the rotation of the Earth around the Sun. But the Romans, who built the first roads, aqueducts, baths, and security walls, didn’t have the comfort of an earth sciences textbook. They needed the powerful beings of religious imagination to explain why the world doesn’t end when winter comes and the food sources die. The story of Pluto and Proserpina explains why the world is warm one moment and freezing six months later. Pluto, the god of the underworld, falls madly in love with Proserpina, daughter of the harvest goddess Ceres. Ceres, whose good will powers agriculture, goes on a climate-ravaging rampage, flooding and scorching the earth’s food crops. In her grief, she brings humanity to the edge of starvation. But the gods need humanity. So Pluto brokers a deal with Ceres to share Proserpina. When she is with her mother, the world is spring and summer. When she is with Pluto, Ceres moderates her grief into a survivable winter. When in Rome is a new look at Roman gods, such as Pluto, Ceres, Jupiter, Mars, and Venus, as well as heroes like Hercules, Perseus, Jason, and Medea. Author Lynn Hamilton mines original Roman sources — Ovid, Apuleius, Virgil, and Hyginus — to uncover what is most enduring in this canon of ancient stories.