80's fantasy movie title or info (or 70's)
I want to remember a movie I saw once when I was a very little kid. I think it's from the 80's, but maybe it's older -i can't tell. All I can remember is that it was a fantasy movie, the main character was a kid or a young boy. I recall a specific scene of the movie, where the boy must climb a very very long... ladder (?), outdoors. I can't recall where that ladder headed to, or if it was part of a larger structure. The atmosphere of the scene was dark. Maybe the entire picture was at night time, or had a dark atmosphere. Maybe the most significant data I can recall is that the boy seemed to wear something like a monk's robe... maybe he was a part of a group of people who all of them weared that same clothes.
I tried to remember the actor of the boy's character, but my memory tricks me: I remember the face of Christian Slater, but that is most probably false. That image from Slater is probably mixed in my mind from "The name of the rose" (where Slater plays, in fact, a monk)
I can't remember anything significant from the plot. All I have is this general idea: a great disaster will happen in the world if the boy does not accomplish an important task/mission (don't know if it's a fantasy world, or an extraterrestrial world, or what).
...
And, I'm not quite sure about it, but there might be some time/dimensional travel involved in all of this.
Well, that's it. I'll be gratefull if anyone recalls anything about this movie.