Inspired by the true story of the Keddie Murders, an unsolved 1981 quadruple homicide that occurred in the town of Keddie in the USA. The murders took place in cabin 28 on the evening of April 11, 1981. The victims were Sue Sharp, her son John and his friend, Dana Wingate. After the crime was discovered Sue's daughter, Tina, was reported missing. Her skull was recovered in 1984 in Camp Eighteen, California.
Shot entirely on location at a 7 cabin resort in Trefeglwys, Mid Wales, which the filmmakers took over for filming in February 2017.
The shot of a running Tina being stopped in her tracks by the headlights of a car is an homage to a shot of Alice (Adrienne King) in 'Friday the 13th' (1980) when she first encounters the character of Mrs Voorhees.
Some of the costumes are modeled on characters in the first four entries of the 'Friday the 13th' series. Most notably, the character Dana wears a denim vest and yellow T-shirt combination which closely resembles one of the costumes worn by the character Ted in 'Friday the 13th: The Final Chapter' (1984).
Although inspired by a real life case, the following disclaimer was added to the start of the film to leave audiences in no doubt that the film is a work of fiction with no resemblance to actual events: "The following film is inspired by true events which are a matter of public record. However, this is not a documentary. All events and person depicted herein have been exaggerated for dramatic effect to create a fictitious work of entertainment. The story, all names, characters and incidents depicted in this production are entirely fictitious and no identification with actual persons (living or deceased), places, buildings and organizations is intended nor should be inferred."