In the dystopian world of Kelsey Egan’s Glasshouse, the most valuable resource is one’s mind. The memories and rituals that remind one of who they are are worth killing to protect.

Egan keeps the details of society’s collapse contained to a few stained glass windows that ordain the glasshouse that the central characters reside in. What is clear is that an airborne toxin known as The Shred has erased people’s memories. Those who survived have had to air seal their homes and wear makeshift space helmets when venturing outside.

This is the life that Bee (Jessica Alexander) and her three siblings–middle sister Evie (Anja Taljaard), lone brother Gabe (Brent Vermeulen), and youngest sister Daisy (Kitty Harris)–now endure. Living with their mother (Adrienne Pearce) in the isolated house, the family does not take kindly to anyone who dares to breach their sanctuary. Shooting trespassers on site, and ritualistically using the remains to fertilize their land, they will stop at nothing to keep The Shred at bay.

Their disciplined sense of order is tested one day when, while on guard duty, Bee is reluctant to kill a mysterious man, The Stranger (Hilton Pelser), who emerges out of the woods. Deciding to bring the wounded man into their home, thus ensuring that the family is obligated to nurse him back to health, Bee’s action immediately causes fractures in the pillars of the once unshakable family.

A strong advocate for not veering from the established rules and rituals, Evie is convinced that The Stranger is a threat to everything they have built. Furthermore, she worries that Bee’s assessment of his character is being clouded by lust. As sexual desires become the key that unlocks the door of buried family secrets, loyalties and longstanding roles within the family are soon tested.

Slowly building on its intriguing premise and playing like a South African version of The Beguiled at times, it takes a while for the film to find its footing. However, much like the stranger who arrives unannounced, the Glasshouse weaves its way into your mind and lingers there.

Egan’s film makes one reflect on how rituals can be used to both provide solace and maintain longstanding falsehoods. The characters may believe that their practices will help them to always remember their roots but, similarly to a person who prepares a family recipe just the way they were taught, they rarely question the origins of the ceremonial acts in which they regularly participate.

Such blind worship is susceptible to ruptures when emotions and physical urges are not factored in. As if a car battery has been jumpstarted, the reawakening of Bee and Evie’s sexual senses reignites memories that they had once locked away.

The suppression of past events and traumas is an important theme that permeates the margins of Glasshouse. For all the talk and fear about loosing one’s memory, Egan’s film ponders if some recollections are better left forgotten due to the immense pain and guilt they cause.

While the film’s science fiction premise offers an intriguing gateway for reflecting on memory and trauma, the measured pacing occasionally works to the Glasshouse’s detriment. Egan keeps many of the secrets too close to the chest for far too long. The major revelations are crammed into the final fifteen minutes of the film and does not give the audience time process them properly. As a result, the ending never hits with the jaw-dropping impact it is clearly meant to enjoy.

While Egan’s slow-burn tale is a rocky journey at times, the film is not easy to forget. It is said that those who live in glass houses shouldn’t throw stones, but Glasshouse shows that the secrets that are buried under the stones hurt the most.

Glasshouse plays virtually at the Fantasia Film Festival on August 18th