Part 1: The Black Storm
Antiope is the daughter of the tribe's female leader and everyone expects her one day to take over the position from her mother. She and her sister, Litta, are skilled warriors, but when they are in battle one day, Litta gets into great danger. 
Antiope begs Tivaja, the Great Lioness, for help, so she can rescue her sister. She promises to give her life to the Goddess if Litta survives.
Suddenly, she is turned into a furious lioness which chases the enemy away.
Litta has been saved, but Antiope can no longer be a warrior or become leader of the tribe. Instead, she must serve the Goddess as one of the Lioness's Daughters under her aunt, Asteria. She hates it. In her heart, she is a warrior, but she can't run away from her promise.

Extract:
"Didn't you see the man's wounds?" asks Litta.
She looks around the other warriors.
"Did any of you see the dead man's wounds?"
Gau steps forward.
"I saw them."
"What you saw – were they the marks of a knife?" asks Litta.
"No, his body had been ripped to shreds," says Gau.
There is a deathly hush in the tent. Everyone is looking at Litta. She points at Antiope.
"Tivaja took over her body. She became the Great Lioness. I saw it myself."
Asteria gets to her feet.
"If that's true, she belongs to me."