For the last twenty years, Annette Chambers has been haunted by the same recurring nightmare of her beloved twin sister's death. When a cryptic stranger warns Annette that she is in danger of being murdered -- just like her sister -- by an ancient evil that dwells between dreams and reality, Annette initially dismisses the idea until she is attacked in her sleep by an unseen entity. Annette soon learns what she experienced is known throughout history as Old Hag Syndrome, a horrifying affliction that causes victims to awake, paralyzed, unable to scream while they are tormented by hallucinations. Soon Annette realizes the Old Hag she faces is real and has been killing off her friends and family. Her nightmare becomes a frightening reality where the only hope of survival lies somewhere between death and madness. Old Hag Syndrome is based on a real and terrifying condition that affects thousands worldwide.