Aubrey Davis travels to Tokyo after her bedridden mother reveals that her sister, Karen, is hospitalized there. Karen had survived the fire she set in a haunted house in the city, a place where a violent supernatural curse originated after a man murdered his wife, Kayako, and their son, Toshio. During a visit to the hospital, Karen is fatally pulled from the building by the ghostly entities. Determined to understand what happened, Aubrey teams up with Eason, a young journalist and photographer who has been investigating the curse.

The vengeful spirits, marked by Kayako’s distinctive death rattle and unnatural movements, do not remain confined to the burned house. The curse has spread, infecting anyone who comes into contact with it. In a separate storyline, a new American student at an international school in Tokyo, Allison, is pressured by popular classmates Vanessa and Miyuki to enter the infamous haunted house as a hazing ritual. After their visit, the trio finds themselves relentlessly pursued by Kayako and Toshio.

Simultaneously, in Chicago, a family begins to experience strange phenomena. Trish moves in with her boyfriend Bill and his two children, Lacey and young Jake. Jake, still mourning his late mother, grows suspicious of the strange behavior coming from the neighbors’ apartment. He soon realizes that a dark presence connected to the Tokyo curse has followed them home, turning their everyday life into a terrifying ordeal. These three seemingly unrelated groups are drawn together as the infection of the grudge expands beyond a single location, demonstrating that there is no escape from the rage that binds the spirits to the world of the living.