This is one of the finest spaghetti westerns, although it's not as well known as Sergio Leone's work or Corbucci's other classic Django. The reason is perhaps that morally it's too complex for mass appeal as we viewers, especially in westerns, prefer to know who the good guys are and who the bad guys are, then cheer as the bad guys go down in a hail of lead.
In the unusual setting of a snow-bound winter (there's a traditional view that snowy westerns aren't as popular as sweaty ones) the townsfolk of Snowhill are suffering. With food scarce they revert to stealing to eat. Ruthless bounty hunters are called in to bring them to justice. When the nastiest hunter Loco shoots up an innocent man, the dead man's wife hires Silence, a mute gunslinger, to kill Loco...
This film is a brutal masterpiece with a level of violence that few movies could equal, and yet there is subtlety with clever scripting and good performances, most notably from Klaus Kinski in a particularly nasty role even for him. Throughout, the story blurs the traditional depiction of right and wrong. Spaghetti westerns became popular by having anti-heroes who act as viciously as the bad guys. But this film goes further. The good guys are outlaws, forced to steal through hunger, and the bad guys are bounty hunters, motivated by personal gain only. Even the law is depicted as being ineffective and ill-thought out, exploring in a way few other westerns have the dubious principle that killing a man can be justified as self-defence only when the other guy goes for his gun first.
This twisted morality clearly has a subtext, and pleasingly the film doesn't preach it and nor does it provide an answer, leaving it to the viewer to interpret for themselves what it says about life during this time of expansion, and now. That aside, ultimately the film's immortality comes from its ending, which I won't describe to avoid spoilers, other than to say it's memorable and one that works because so few other films have done it. If you like westerns, this is a must see film. Just don't expect Shane.