Whole movie was filmed in Bozidara Adzije library.
Early concepts had an alternate ending of the movie where Danijel's character is shown in the post-credit scene where he hangs the picture on the wall. Suddenly, he hears the door of the archive opening and sees the picture falling off the wall. However, that scene was never filmed due to the fact that it felt too cringe.
Prequel for this movie was in various stages of development. Plot supposed to evolve around Danijel's relationship with his co-workers before Fran was even hired in the library. However, the idea for the prequel was scrapped preliminary to pre-production status.