BOOK 1: BLACK UNICORN
Tanaquil lives with her mother and despises her annoying and foolish uses of magic. Therefore, she doesn't think go highly of sorcery in general. Tanaquil's life doesn't seem to be going anywhere until a strange little rat dog called a Peeve begins to start visiting her and brings with him a shiny bone.
When the Peeve digs up more of this skeleton, Tanaquil uses her talent to mend it. The restored black unicorn guides her into a perfect world and grants protection to her and the Peeve.
Tanaquil must accept her gift for mending makes her a type of sorcerer. The Peeve, of course, is her familiar (and I want one).


BOOK 2: GOLD UNICORN
Tanaquil mends a huge golden unicorn for her sister. This unicorn is meant to be a symbol of the young woman's power as she moves to conquer lands, and Tanaquil hopes that it will frighten the people into surrendering and lesson the loss of lives.
In this story, Tanaquil deals with confusion over her sister, a journey through a hellish sort of world, strange allies and pets, and the complications of love.


BOOK 3: RED UNICORN
Here, Tanaquil ends up in a world that reflects her own in many ways. There is a person here for every person in her own world, including a girl named Tanakil that is her double. As Tanaquil tries to get over her lost love from book 2, she has to adjust to this strange new place (where she soon realizes she can do pretty much anything she thinks of) and try to help Tanakil (who is so intent to keep her love that she makes plans to kill her sister).
The people of this world suspect something strange is going on, but they don't know what or how. There are sightings of a red unicorn, but people only catch a glimpse. And Tanaquil must stay until she learns what she has to to find her way back.