The Abduction of Persephone (or Kore, the maiden).
Daughter of Zeus and Persephone
Abducted by Hades and taken to the Underworld as his Queen

Demeter Mourns
Demeter can't find her daughter...finds out from Hecate that she was abducted. Finds out from Helios exactly to where she was abducted, and by whom. In her grief, Demeter wanders and comes to Eleusis. Know the outline of the story: Demeter disguises herself, is found by members of the royal family at the well, is taken in as a nurse to the royal baby (Demophoon) by his mother and father (Celeus and Metaneira).

What is special about Demeter - how can you tell she is a goddess?

Who is Iambe and what does she do?

What is kykeon?

How does Demeter try to give immortality to the baby?

Demeter's Grief: She continues her search for Persephone, and in the meantime neglects the earth. Everything dies, and a famine comes upon the land. Why do the gods choose to step in? What has that got to do with them?

How Demeter's anger is assuaged: Know the details of the deal agreed to by all concerned

The Secular Benefits: Demeter teaches mankind how to plant and grow grain by teaching the secret to  Triptolemus (he becomes a sort of divinely ordained Johnny Appleseed of antiquity).

The Eleusinian Mysteries. As in any ritual that derives form myth, the details are designed to reenact the experiences of the god(dess). But since the rites were secret, no one really knows exactly what the point of the mysteries were. But because of the association of the tale with the cycle of birth and death (Persephone's return form the underworld every spring, and the rebirth of the earth), it is assumed that the Eleusinian Mysteries was a religious ritual that assuaged the fear of human beings in regard to death. In other words, it offered insight into Life after Death. If you believed and worshipped the goddesses Demeter and Persephone, you would be rewarded with life after death.

Eleusis is a town about fourteen miles west of Athens, which adopted the mysteries as part of itsa state religion. Feel free to check out these images on my own Eleusis website, including the Triptolemus relief, which you must know about). The Perseus Project offers these links:

Overview of the site of Eleusis as sanctuary
Overview of the Eleusinian Mysteries (Perseus)

Know that Hiera means "sacred objects" even though we don't know what that means, and know that the the Hierophant is the one "who reveals the Hiera," the sacred priest of teh mysteries.