Writer/director Christian Tafdrup got the idea for the movie from his own experience while on holiday in Tuscany, where his family met a friendly but somewhat socially-awkward couple from the Netherlands. They got on very well and the two families spent a lot of time together. When Tafdrup returned home, he got an invitation from the Dutch family to stay with them in the Netherlands. Tafdrup briefly considered the offer, but decided not to take it, since he felt it would be odd to stay with people he didn't really know. He never met them again, but couldn't stop thinking about what could have happened had he accepted, and some of his darkest ideas became the basis for his screenplay. Tafdrup stresses that the movie is no more than a dark fantasy, and that the Dutch couple from his own holiday were undoubtedly fine people.
AMC Networks' premium streaming service Shudder acquired the film rights in January, ahead of the film's world premiere at the Sundance Film Festival.
The Italy sequences at the beginning were actually filmed last.
An American remake of the film will be released in the United States by Universal Pictures, in September 2024. James McAvoy plays the "Patrick" character, although renamed "Paddy".