Stalker
Stalker is quite a peculiar film.
In essence, Stalker is a very philosophical film hinged on the nature of not only desire but the essence of human beings.
"What comes true here is that which it reflects the essence of your nature."
Tarkovsky uses metaphysical and moral dialogue to hinge on the philosophical premises of the film regarding human nature and desire.
The main premise of the film is centered on the effect of desire, specifically on the fear of attaining such.
Why would we be afraid of attaining our desires?
Tarkovsky knew that desires are not merely a surface-level wish manifested by our minds but a reflection of who we are, made manifest.