The Treasure of Sierra Madre offers its rewards in how the story is told rather than what ultimately happens. Early on, Howard, played by Walter Huston, explains the basic premise: “There's never been a prospector who died rich… going with partners is risky. Murder’s always around. Partners will accuse each other of all sorts of things … as long as there isn't any gold found, everyone gets along, but when piles of it start to appear, that’s when the problems begin.” The film then progresses with a sense of certainty like in ancient tragedies (with Howard surpassing even Cassandra, since he doesn’t listen to his own warning). Knowing where the story is headed, writer/director John Huston doesn't hurry to reach the conclusion; instead, he takes his time developing the characters and setting up the situation, showing considerable patience and including some humor—like a scene where Bogart splashes water on a baby played by Robert Blake. Once the three main characters – Howard, Fred C. Dobbs (Humphrey Bogart), and Bob Curtin (Tim Holt) – ascend the mountains named in the title, and Dobbs loses his grip on reality, everything unfolds as Howard predicted—which is to say, disastrously, but also impressively; Dobbs grows paranoid and irrational, believing that the others will either betray him or lie in wait—but won’t simply shoot him outright, because they are “yellow.” Even when portraying a hero, Bogie always seemed to have a dark side. Rick Blaine is a cynical, bitter drunk who, as only happens in movies, is Saved by the Love of a Good Woman (even if he doesn't Get the Girl at the End), and Sam Spade is constantly looking out for himself. It’s in films like The Treasure of Sierra Madre (similar to Conflict and In a Lonely Place) that he allows that inner darkness to surface, something he only touches on in other roles, and his slide into insanity remains the highlight of an excellent film—and even then Huston manages to work in some humor, such as when Dobbs asks someone “who’s not civilized?!” just before punching him.

Source on TMDB