Growing up in a devout household, Grace was always told she was special and would change the world. She was a Holy Child, born on Palm Sunday. Her childhood was spent in church, Latin lessons, and prayer. She was shunned by her classmates and community. More than anything, she just wanted to be normal. The one person who let her be herself was her best friend, Aaron. Together as outcasts, Grace and Aaron faced their difficult childhoods together until he was forced to move away.

Life pressed on for Grace as her mother kept trying to force her into the church not knowing that Grace had a secret and its name was Onoskelis.

Onoskelis was a demon who took the form of a beautiful woman, entranced men, and strangled them. As a Holy Child, Grace was able to communicate with the demon who taught her how to walk, talk, dress, and seduce. Together, they took out deadly revenge on the men who broke Grace's heart.

Eventually, Grace moved away from her overbearing mother, left the church, and exceled in a career as a museum curator. But, when Aaron returned to her life, Onoskelis decided it was his turn to die. Grace must fend off the demon who made her the woman she became in order to protect her childhood best friend and the love of her life.