Erin has spent most of her childhood in the psych ward of the hospital. Whenever she is under extreme stress, her violent alter-ego Shevaun takes over and paves a path of destruction, which Erin can never remember later.
But Shevaun is more than a part of Erin's imagination. She exists as a powerful, centuries-old vampire. Shevaun is fierce, independent - so nothing good could come of the two actually meeting.
Nearly 10 years after her first novel was published at age 15, Atwater-Rhodes is still going strong. Persistence of Memory is not labeled as part of a series, but it ties together the Kiesha'ra and Den of Shadows with a few well-planned characters. I had that "aha" moment in one particular scene that said, "Yeah, shapeshifters and vampires and witches all belong in the same universe."
As far as the characters and plot are concerned, I was captivated. Erin and Shevaun are totally different people - thus the alter-ego horror - but there is actually a strange similarity to them. In addition, the supporting cast have complete backgrounds and personalities, which are fit comfortably into the main plot. And the plot? Loved it. Go read to see why.