During a sleepover, high schoolers Tomoko Oishi, Yuko Takeuchi and Masami Kurahashi, Hitomi Sato, dive into a chilling urban legend about a cursed videotape that dooms anyone who watches it to die in seven days after a foreboding phone call. Tomoko reveals that last week she and her friends watched a mysterious tape and then received an inexplicable call. As Masami heads to the bathroom, Tomoko witnesses the TV switch on by itself and is suddenly killed by an unseen force, leaving a creeping sense of dread in the room.
Reiko Asakawa, Nanako Matsushima, Tomoko’s aunt and a journalist digging into this strange legend, attends Tomoko’s funeral and learns that three of Tomoko’s friends who watched the tape with her have died in the same manner. Reiko pieces together fragments of the mystery and uncovers an unmarked videotape hidden in a resort cabin where the four stayed. The footage shows a rapid sequence of seemingly unrelated images, punctuated by harsh screeching sounds, and ends with a haunting shot of a well that feels almost alive with menacing presence. After watching it, Reiko is confronted by a vision and receives a phone call filled with the same screeching noise, convincing her that she, too, has been cursed. Determined to escape the fate, she takes the tape with her and leaves the cabin behind.
To unravel the curse, Reiko seeks help from her psychic ex-husband Ryūji Takayama, Hiroyuki Sanada. They study a copy of the tape Reiko made and stumble upon a cryptic message spoken in an Ōshima dialect, which hints at a place to investigate further. The pair plan a journey to Ōshima to trace the origins of the legend. Before they depart, Reiko discovers that Yōichi, her and Ryūji’s son, has also been drawn into the mystery after being pressured by Tomoko’s circle to watch the video.
In Ōshima, Reiko and Ryūji uncover the backstory of Shizuko Yamamura, the woman depicted on the tape. Before Shizuko’s mysterious public demonstration of psychic abilities, she had a fraught affair with ESP researcher Dr. Heihachiro Ikuma, Daisuke Ban. When they confront Shizuko’s cousin Takashi, a vision reveals that during the demonstration Shizuko’s young daughter Sadako psychically killed a journalist who criticized her abilities. Unable to locate Sadako, Reiko realizes that Ryūji never received a phone call after watching the tape the way she did at the cabin, so they hurry back to the cabin to search for answers.
Their investigation leads them to a sealed well found in the cabin’s crawlspace. A new vision reveals that Dr. Ikuma trapped Sadako inside that well, preserving her there. The two conclude that Sadako remained alive and that the infamous curse was born when a videotape somehow recorded the rage she projected. They drain the well and discover Sadako’s remains. By the end of seven days, Reiko appears to have broken the curse when she survives the initial deadline, but the nightmare continues.
The following day, Ryūji’s television turns on by itself once more, revealing the same well at the end of the tape. Sadako’s vengeful spirit crawls from the well and emerges from the TV, advancing toward Ryūji and killing him. Reiko, who hears his final moments over the phone as she tries to call him, is guided by a spectral presence to an unsettling realization: the only way to survive may be to propagate the curse—copy the tape and show it to someone else within seven days. Desperate to save their son Yōichi, Reiko races to her father’s house to share the tape and break the cycle, hoping to spare him from a similar fate.
