However, Demeter had not forgotten her daughter, and for her sake she caused famine in the whole earth for an entire year, threatening to destroy mankind. It was then that Zeus´attempt to persuade Demeter to return to Olympus, but Demeter refused to go. Demeter declared that she would never set foot on Olympus again, nor let the earth bear fruit, until she beheld with her own eyes her daughter Persephone.In order to solve this dilemma, Zeus sent Hermes to the Underworld to fetch Persephone back. Hades obeyed Zeus' request, but before Persephone left, he gave her a pomegranate seed to eat so that she would be bound to him. Hermes took Persephone to her mother and there was a joyous reunion until Demeter learned that Persephone had tasted food in the Underworld, since for having done so she would have to dwell in the Underworld a third part of the seasons every year. It was agreed than that Persephone would stay one third of the year in the Underworld and the two thirds with the Olympians. Demeter then allowed the grain to grow again, and the famine was averted.Her daughter Persophone must leave her to spend some of the year with her husband, in doing so makes Demeter sad, and so everything she cares for dies (Autumn and Winter). But soon Persophone comes back and Demeter is overjoyed to see her daughter again, so everything comes to life again (Spring and Summer).