From time to time I tune in to mythical beings. Often, they inspire my work. This has seldom been more strongly true than with Inanna.
Inanna in History
Inanna is a goddess of ancient Sumer. The stories about her, which survive in hymns and records of rituals, are among the oldest in the world. She was worshipped as the Queen of Heaven and Earth, considered a goddess of justice and war as well as of love and fertility. In the sky, she was identified with the planet Venus. In later times, her cult combined with that of the Babylonian Goddess Ishtar, and later the Eurasian Aphrodite (1)
In this image from a Cylinder seal dated about 2300 BCE, Inanna is shown with wings and fully armed. Her foot rests upon a lion (one of her emblems), while an eight-pointed stars hangs above her shoulder, representing Venus. 
How I Met Inanna
Five years ago, I was working on Ghosts of Lock Tower, the third of the Abby Renshaw Supernatural Mysteries. One day, the above image of Inanna showed up on my FaceBook feed. Later that evening, while I was reading a book about magic, I found myself staring at the very same image on the page. That night, I had a recurring dream in which a woman kept coming into my bedroom and shaking the bed.
Now, I may be dense. But an ancient goddess only has to disturb my sleep a few times before I pay attention. Plainly, Inanna had something to tell me. I started researching her. She ended up playing a key role in the plot of Lock Tower, serving as a spirit guide for Abby on her quest.
But how would the presence of a Sumerian goddess make sense in our world (even in fiction)? Abby wondered that too. She asked Kevin, a retired Anthropology professor and one of her mentors. He offered several ideas:
“I can see maybe three ways. One, she’s an element of your personal unconscious that you’ve activated by magic. Two, she’s a figure of the collective unconscious that you’ve drawn into yourself by magic. Three, she’s the spirit of a real ancient goddess who has always existed in the world, waiting for humankind to reawaken her.”
“Good answers. Which is it, I wonder.”
Kevin laughs. “My guess? All of the above.”
Journey to the Underworld
Surely the most famous story about Inanna is of her descent into the Underworld. According to Wolkstein and Kramer, this myth exemplifies:
“…the path of the descent (which) has impelled the mystic since the beginning of recorded human experience. In many traditional societies, initiatory tribal rites are often characterized by a symbolic descent into and ascent from the labyrinthine Earth Mother.” (page 156).
The same idea is played out in later descent myths, such as that of Demeter and Persephone, and Orpheus. It was also the theme of mystery cult initiations, such as the famous rites of Eleusis.
In the case of Inanna, the myth again resonates with the planet Venus. With its orbit close to the Sun, Venus is sometimes seen in the morning sky and sometimes in the evening. And sometimes it remains below the horizon and is not seen at all. In other words, like Inanna, it journeys from the Great Above to the Great Below, and is at times stationed in the Underworld.
In the Sumerian myth, Inanna decides she must leave all of her Earthly temples to visit the Great Below, the realm of the dead, which is ruled by her older sister, Ereshkigal. Inanna adorns herself with royal garments and symbols of her power. But Ereshkigal has decreed that she must surrender these attributes, one by one, as she passes the seven gates to the Underworld. Inanna arrives stripped of power and Ereshkigal “fastens the eye of death upon her.”
When Inanna does not return after three days, her loyal servant Ninshubur, pleads for the gods of heaven to free her mistress. The first two refuse, but then Enki, the God of Wisdom, fashions two creatures and sends them below to rescue Inanna. So the goddess is reborn and returns to her rightful place in the world above.
Myth to Fiction
In Abby’s latest adventure, A Demon on the Lion Bridge, the myth of Inanna again plays a role.
Abby is working as a law intern in St. Augustine, Florida, when she encounters a demon that has haunted the city since earliest time. This demon feeds on human dread and despair. Abby tries again and again to banish the creature. Each encounter weakens her, until at last she falls into despair. Lost in the spirit realms, thinking she will never escape, she calls out to Inanna for help—just as Ninshubur called out to the gods of heaven.
A single candle glows. The light flickers on walls painted with murals. I’m seated in a heavy chair, like a throne, dressed in a long skirt, fringed shawl, gold jewelry—like the priestesses of Inanna wore in ancient times. But when I try to stand, my arms and legs won’t move. I am chained at the wrists and ankles.
“It appears you are trapped in the Great Below, my priestess. Even as once I was.” Inanna floats in front of a bolted iron door.
“How can I escape from here?”
She pauses a moment, considering. “I shall send spirits to try to free you. That is how I was freed.”
As promised by Inanna, certain spirits do come to Abby’s aid. Like Inanna, she is able to return to the world of the living—for a final confrontation with the demon.
To learn how that turns out, read A Demon on the Lion Bridge, available on Amazon. 
(1) See Inanna, Queen of Heaven and Earth by Diane Wolkstein and Samuel Noah Kramer.(1983)