Synopsis:

In the 1600s, a priest is summoned to a remote cabin deep in the woods, where twin sisters have fallen victim to an ancient evil. One is possessed by a demon. The other is covered in strange writing. With exorcisms still centuries away, the only way to protect their bloodline is to kill both girls simultaneously and consecrate their bodies before the curse spreads.

In the present day, Amie has just buried her last living relative, her grandmother. The closest thing she has to family is her best friend, Shannon, with whom she shares a lively house alongside brothers Jess and Nick. Together they've built the kind of family that isn't defined by blood, but by choice.

The day after the funeral, Amie confides in Shannon about the only inheritance her grandmother left behind: a handwritten letter and an intricately carved wooden box that has been passed down through her family since the 1600s. As they read the letter together, they discover the box was never meant to be opened, for fear of ending the family bloodline. Only then does Amie admit the seal has already been broken. Inside, they find a vial of water wrapped in a rosary and an ancient leather-bound book containing pages of handwritten passages.

As the day unfolds, Amie is overcome by a mysterious illness and begins experiencing vivid dreams of two sisters, Ann and Sarah, living in a secluded cabin deep in the woods. Through these visions, she witnesses Ann turning to witchcraft in a desperate attempt to change her family's fate. With each dream, the line between past and present begins to blur. By sunset, ancient markings have spread across Amie's body, and Ann has claimed her as its new host.

Determined to reunite with the sister she lost centuries ago, Ann plans to resurrect Sarah using Shannon as her vessel. As the curse tightens its grip, the house is pulled back into the forests of the 1600s, trapping everyone inside the very place where the nightmare began. One by one, their friends are murdered as Ann closes in on her true prize. With Amie slipping further beyond her reach, Shannon must break a curse four centuries in the making before she loses both her best friend and the family they've built together.