When Rachel turns 18, her alternate personality revolts in a wicked struggle for control over their shared body. Each time Rachel's "other" get outs, bad things happen.

In a desperate attempt to save her sanity, Rachel uncovers an ancient curse that could be a clue to her struggles.

Caught in a violent turmoil of destiny, Rachel turns to all the wrong people for help and soon discovers a plot against her that dates back to 11th century Scotland.

As Rachel faces down the diabolical instincts fired by her "other", she draws on the last reserves of hope that have kept her sane in a life of madness.