The film is loosely based on the 1972 Faraday School kidnapping of a teacher and her class by Edwin John Eastwood and Robert Clyde Boland. Eastwood later escaped from prison and repeated the crime with another teacher and his class in 1977. The Faraday kidnapping was in turn a real-life copycat crime based on a scene in the Clint Eastwood film Dirty Harry (1971) where the Scorpio Killer holds a bus driver and several schoolchildren hostage.
The production was made as a tele-movie made for American audiences for the HBO pay television network and as as theatrical feature film for the Australian market. The picture debuted first in the USA in 1985 with it being released into Australian cinemas in 1986.
Cast member Vernon Wells would later go on to star in another movie called ''Fortress'. This was the 1992 science fiction action feature film "Fortress" which was also an Australian production. Crew members, producer Michael Lake, costumer Phil Eagles and stunt co-ordinator Chris Anderson, also worked on both productions.
Casting the lead role of Sally Jones proved troublesome; HBO agreed to put up half the film's budget if the role was played by a well-known actress. At the time, Actors Equity, the Australian actors' union, was known for challenging or blocking Australian film productions that cast foreign actors in leading roles instead of Australians, and they refused to allow production to proceed with Crawford and HBO's original choice for the role, Bess Armstrong. Eventually, all three parties settled on casting Sigrid Thornton, but Thornton was dropped two months prior to the scheduled start of shooting due to pregnancy, and pre-production was cancelled entirely when Equity refused Crawford's ultimatum to allow them to cast Armstrong. However, the film re-entered pre-production three months later following the casting of Rachel Ward. Although Equity supported her casting, Ward, who is English by birth, had mostly appeared in American films, and had only recently migrated to Australia with her husband and Die Dornenvögel (1983) co-star Bryan Brown.
The main large fortress cave was a set construction because a suitable cave at the main cave filming location of the Buchan Caves could not be found. The Crawfords Productions website once re-published material from the film's production notes that stated that the production was: ''Shot on location in the Bainsdale area. Some cave scenes were shot in the Buchan Caves. The fortress cave was constructed after failing to find a satisfactory location. It was built in the Grampians countryside using 27 tonnes of scaffolding; 5 trucks of concrete; 3,500 metres of chicken wire; countless wooden boxes; 2,000 metres of hessian; 300 litres of paint; 1,000 metres of fencing wire and 12 drums of polyurethane. It took eight weeks with a crew of nine living in the bush working about 12 hours a day. [Philip] Warner [Phil Warner], the [production] designer, also built a series of man-made interiors for the inside of the Fortress and two spectacular caves. These were built in a large warehouse outside Beveridge, Melbourne.