This article analyzes the process of transformation of “A Picnic onRoadside”, a science fiction novel written by the Strugatsky brothers, into AndreyTarkovsky’s movie “Stalker”. Despite the fact that Tarkovsky himself said the sci-fisection of the film was no more that a strategic trigger that helped to reveal thekey ethical conflicts, up to now, there has been no attempt to compare the film“Stalker” with the original novel in order to understand the director’s intention.This article aims to look into what made him choose the novel and how he turnedit into a movie.Tarkovsky found the shelter for souls and hope in “A Picnic on Roadside”.In other words, he found the psychological and existential clues that could becombined with material from Dostoyevsky’s works.The stalker described by the Strugatsky brothers was a kind of predatorselling mysterious things in the forbidden zone, whereas the stalker describedby Tarkovsky functioned a priest who guides the lost or miserable souls tothe sanctuary to realize their desire and hope.Furthermore, the stalker’s attitude toward life in the movie incorporatesDostoyevsky himself who experienced Siberia and is reminiscent of bothRaskolnikov from the novel “Crime and Punishment” and Myshkin, the maincharacter of the novel “The Idiot”. Just like Sonia of “Crime and Punishment” andMyshkin of “The Idiot” discovered God through the image of the “holy fool”, sothe stalker, his wife and daughter discover the fullness of God through their flaws.This “kenosis” attribute is the basis of the fullness of Dostoevsky’s work,which inherits the spirit of the Russian Orthodoxy. In the final script, Tarkovskytransforms the “forbidden zone” into a sacred space. The path of the charactersheading toward the “zone” is “the exploration of their human mind”. The “Stalker”is a philosophical meditation.