When imaginative eleven-year-old Emma and her parents and friends go to a remote island in the Pacific Northwest during the summer of 1985, she thinks it’ll be a normal family vacation.

But when she starts dreaming of her loving Grandma Virginia killing people, she realizes there’s more to the sweet matriarch than she thought. And when she has a premonition that her grandmother intends to kill her husband, she knows she has to take matters into her own hands.

When she foils Virginia’s first plan to murder Grandpa Roy, Emma becomes a target herself.

Allied with her friends, Emma must differentiate between make-believe and psychic visions to try to save both her grandfather’s life and her own.