Treci Kljuc on AllMovie

In this tightly-wrought, intimate mystery film, a couple move into a new apartment and discover that strange things go on while they are gone -- they seem to be under surveillance, and then they start receiving odd letters with money inside. Strapped for funding, they take the money -- and then continue to become more and more nervous over the inexplicable letters and strange occurrences, especially given the fact that the woman is pregnant and should have some stability at this crucial time in her life.