The oxen drew the plough, but in vain was the seed sown in the prepared ground. Mankind was threatened with utter annihilation, and all the gods were deprived of sacrifices and offerings. Zeus endeavoured to appease the anger of the gods, but in vain. Finally he summoned Hermes to go to Pluto and order him to restore Persephone to her mother. Pluto yielded, but before Persephone left she took from the hand of Pluto four pomegranate pips which he offered her as sustenance on her journey. Persephone, returning from the land of shadows, found her mother in the temple at Eleusis which had recently been erected. Her first question was whether her daughter had eaten anything in the land of her imprisonment, because her unconditional return to earth and Olympos depended upon that. Persephone informed her mother that all she had eaten was the pomegranate pips, in consequence of which Pluto demanded that Persephone should sojourn with him for four months during each year, or one month for each pip taken. Demeter had no option but to consent to this arrangement, which meant that she would enjoy the company of Persephone for eight months in every year, and that the remaining four would be spent by Persephone with Pluto. Demeter caused to awaken anew "the fruits of the fertile plains," and the whole earth was re-clothed with leaves and flowers. Demeter called together the princes of Eleusis--Triptolemus, Diocles, Eumolpus, Polyxenos, and Keleos--and initiated them "into the sacred rites--most venerable--into which no one is allowed to make enquiries or to divulge; a solemn warning from the gods seals our mouths." Although secrecy on the subject of the nature of the stately Mysteries is strictly enjoined, the writer of the Homeric Hymn to Demeter makes no secret of the happiness which belonged to all who became initiates: "Happy is he who has been received unfortunate he who has never received the initiation nor taken part in the sacred ordinances, and who cannot, alas! be destined to the same lot reserved for the faithful in the darkling abode." The earliest mention of the Temple of Demeter at Eleusis occurs in the Homeric Hymn to Demeter, which has already been mentioned. This was not written by Homer, but by some poet versed in Homeric lore, and its probable date is about 600 B.C. It was discovered a little over a hundred years ago in an old monastery library at Moscow, and now reposes in a museum at Leyden.