Set in Burleson, Texas, in 2011, the film centers on a 10-year-old girl named Anna Beam (Kylie Rogers), daughter of Christy Beam (Jennifer Garner). Anna is suffering from a pseudo-obstruction motility disorder and is unable to eat, using feeding tubes for nutrition. Upon checking at the local hospital, they find no signs of illness but say it's "acid reflux" or "lactose intolerance", but Christy is not convinced by this. Hoping to discover what is the cause of her disease, Christy and Anna travel to Boston despite not having an appointment with the pediatric gastroenterologist, Dr. Nurko.
When she is subsequently examined at Boston Children's Hospital, evidence of the chronic illness is found. She goes through extensive treatment. During this ordeal, Anna and her mother befriend a local Massachusetts resident named Angela, as well as Ben and his sick daughter, Haley.
In the epic conclusion to the Devil's Deal series, Freya has one final chance to discover the full potential of her own power, and to use it to restore balance in the universe - once and for all. After the destruction caused by Roisin, Ferya and Torix come to terms with their losses and mistakes... And prepare for a final battle that will change everything.