According to the attending priest, the boy attempted to contact his late aunt using an Ouija board, after which paranormal activity started in the home including unexplained noises and an occurrence of a poltergeist-like event involving blankets flying around of their own accord. Robbie then began to show signs of possession, speaking in tongues and blisters and cuts appearing. He was taken to a mental institute in St. Louis where he was treated both mentally and spiritually. It was here that a group of priests started to perform various exorcising rituals to try and extract the demon. After a staggering total of 30 attempts, the priests were satisfied that they had successfully banished the demon from Robbie's body.
After the ceremony he went on to have a very normal life, including a successful career at NASA. If my mother only knew that demon possession could lead to working for NASA, I'm positive that she would have made me play with Ouji boards every night.
Each of the 13 horror stories has a video clip from the film, and many have documentary clips from the stories that inspired them. Link