Ben (Francis Ng) is the producer of a Hong Kong radio program "Horror Hotline". He is busy with work and neglects his girlfriend Helen (Niki Chow). Helen is a nurse who had an abortion without telling Ben. This incident makes her hard to let go and she often sees hallucinations. Mavis (Josie Ho) is a reporter from an American TV news network. She and a photographer and a group of five people came to Hong Kong to shoot a special program about the culture of Hong Kong radio. The first research object is "Horror", but Ben is not friendly and only allows them to shoot outside the live broadcast room. One night, the host of "Horror" received a call from a man who called himself Chris. He said that in 1963, when he and six classmates were playing football in Sai Wan, they accidentally found a "big-headed monster baby" in a cave near the stadium. They were immediately scared to death. Even the principal who believed in Islam could not subdue it with the Koran in his hand. Chris's call attracted an unexpectedly enthusiastic response. Ben and Mavis decided to conduct an in-depth investigation, but the starting points of the two news were different. Almost at the same time, the hospital where Helen worked received an overly frightened teenager Sam (Li Cansen). Helen did not dodge like other nurses, but was affectionate to him. Mavis and Ben found the old principal's adopted daughter Connie (Zhang Jiajia) based on limited clues, and learned from her that Chris had seen the old principal with 6 men not long ago. Later, during the live broadcast of "Fear", the host received a call from Chris again, but this time it was a curse on them. Soon, Mavis's photographer died strangely, and the images he took showed that there was an extra figure in the live broadcast room that night. Mavis and Ben conducted further investigations and found that a pregnant woman did give birth to a terrifying "big-headed monster baby" in 1961, and Chris's 6 classmates had already committed suicide collectively. After Ben proposed to Helen, Helen's behavior changed one night. She came to the hospital and took Sam to a strange place.