The film opens with a short clip showing the parasitic lifecycle of cuckoos, who lay their eggs in the nests of other birds. Once hatched, the cuckoo pushes the mother bird’s young out of the nest and is then tended to by the surrogate mother. By the end of the clip the cuckoo is disturbingly larger than the mother bird, greedily eating all she has to offer. Young couple Tom and Gemma want to purchase a house. They visit a strange real estate agent, Martin, who tells them of a new development called Yonder. Gemma and Tom drive out to the development with Martin where the houses there are identical suburban homes. The place is silent, empty and otherworldly. Martin shows the couple around house #9 and then vanishes. Gemma and Tom attempt to leave Yonder, but become lost; every route returns them to #9. The car eventually runs out of fuel and they decide to stay the night in #9. The next morning, Tom climbs onto the roof to see if he can spot a way out of Yonder. He sees that the houses of Yonder seem to stretch into infinity. The couple decides to follow the artificial-looking sun, hoping it will lead them out if they stay on course. The couple, however, is still led back to #9. They find a delivery box filled with prepacked food and other necessities. A furious Tom sets #9 ablaze, hoping to attract attention. The couple falls into a strange sleep, and awakes outside a rebuilt #9 to find a tiny infant with instructions: "Raise the child and be released." Three months have passed and the infant has rapidly grown to the size of a seven-year-old boy with an adult-like voice imitating Tom's and Gemma's. He incessantly demands attention and closely observes and mimics the couple when he is not absorbed by strange patterns on the television. Living with the boy and their imprisonment takes a psychological toll on the couple. Their physical well-being also worsens. Tom discovers that the soil of Yonder is made from a seemingly artificial substance. He starts to dig a hole and becomes obsessed. Digging makes him feel as if he has a purpose, but the hole just gets deeper and deeper. When he hears noises at the bottom of the hole, he continues digging. Tom's physical and mental health deteriorates further. Tom attempts to harm the boy, but Gemma intervenes. Gemma attempts to understand their predicament by engaging with the boy. She discovers that he is incapable of imagining things or dreaming. Tom's emotional distance pushes her closer to the boy. One day the boy vanishes, only to reappear with a strange textbook in an unknown language, with illustrations of humanoid beings with large throat sacs. Gemma asks the boy who gave the book to him and he shows her by inflating his throat sacs and making alien sounds. After more time has passed, Gemma and Tom have grown weaker. The boy has grown into an adult and Gemma and Tom reunite in their fear of him. The boy leaves the house every day and Gemma and Tom do not know where he goes. While digging, Tom finds a withered corpse in a body bag and afterward, he weakens to the point of death. Gemma begs the boy to help and he provides them with a body bag. Tom dies and is flung into the hole. A vengeful Gemma attempts to kill the boy, but only manages to injure him before he flees into a bizarre, subterranean corridor. Gemma follows and tumbles through parallel homes where other young couples live lives of similar despair. Gemma is then spat back out into #9. After a final act of verbal defiance, Gemma dies. The boy buries her in the hole with Tom and leaves Yonder. He later becomes an estate agent, replacing Martin, who has finished his life cycle. The new Martin rolls up his predecessor’s body and places it into a filing cabinet before assuming his new position. A new couple walks into the office and Martin rises to greet them.
In May 2018, it was announced Jesse Eisenberg and Imogen Poots had joined the cast of the film, with Lorcan Finnegan directing from a screenplay he wrote. The film was shot in various locations in Belgium and Ireland, before moving to Ardmore Studios, Wicklow, Ireland. Vivarium is an Irish–Danish–Belgian co-production.
Release
The film had its world premiere at the Cannes Film Festival on 18 May 2019. Shortly after, Saban Films and Vertigo Releasing acquired US and UK distribution rights to the film, respectively. It was released in the United States, United Kingdom and Ireland on 27 March 2020, with a limited theatrical release and video on demand release on the same day.
Reception
On Rotten Tomatoes, the film has an approval rating 72% based on 130 reviews, with an average rating of 6.57/10. The site's critical consensus reads, "Vivarium may confound almost as often as it intrigues, but this well-acted sci-fi/horror hybrid has interesting ideas -- and explores them with style." On Metacritic, the film has weighted average score of 64 out of 100, based on reviews from 23 critics, indicating "Generally favorable reviews".