Easily one of the most depraved and cruel films I've ever seen. This, along with other films like the 1920 Dr. Jekyll and Mr. Hyde, is a reminder of how powerful films could be in the silent era.
Our protagonist is Phroso, a magician in a tawdry circus act, who finds out one night that his wife, Anna, has been cheating on him with a man named Crane. Crane intends to take Anna to Africa with him, where he plans to become an ivory trader. Phroso doesn't react well to this news and gets in a fight with Crane. Crane, unfortunately, turns out to be a much rougher fellow than he looks and makes short work of Phroso, pushing him over a railing and sending him plummeting many feet to the floor below. Phroso finds himself paralyzed from the waist down after the fight. About a year later, Phroso hears gossip that his wife has come back to town and, in fact, was seen entering the very church where she and Phroso were married. Phroso understandably goes there as quickly as he can, being a paraplegic, only to find that Anna has committed suicide in front of a statue of the Virgin Mary. Next to her, screaming its head off, is an infant girl. Phroso concludes that Crane had abused Anna so throughly as to drive her to suicide and vows vengeance, not only on Crane but on his bastard daughter as well.
Eighteen years later, Phroso has relocated to Africa and begun a new life as Dead Legs, shaman of a tribe of cannibals. His main business is cutting into Crane's ivory profits by using his bag of tricks to frighten the tribes that work for Crane into working for him, instead. Dead Legs has also seen to it that Crane's daughter (whom he has named Maize) has grown up an alcoholic wreck of a person, worse off than even the obviously criminal scum white men that work for him. Dead Legs sends word to Crane that he wants a meeting to discuss a partnership, and has Maize brought to his camp. The next few scenes are of Dead Legs debasing Maize to a lower point than even a mongrel dog. He allows the cannibals to rape her, plies her with alcohol then denies it to her, forces her to eat off the floor, and steals her few meager possessions from her. He also forces her to watch the cannibals' funeral ceremony, during which the wife or daughter of a dead man is thrown onto the funeral pyre along with him.
When Crane arrives, Dead Legs confronts him with Maize, and makes sure Crane knows exactly what she has suffered. Faced with this, Crane ... laughs? It turns out that Dead Legs' revenge scheme, his entire life for the past eighteen or more years, has been based on a rather serious misunderstanding.
You certainly couldn't make West of Zanzibar today, at least without a comprehensive reworking. The stuff about Dead Legs and his treatment of Maize might still fly, but the treatment of the Africans would not. As presented, they are barely even human, so unsophisticated and superstitious that they can be persuaded to treat a white man as a king simply because he performs a few simple magic tricks for them. Actually, I'm not even sure if the way Dead Legs treats Maize would make it through with an "R" rating today. The "torture porn" movies of the 2000s have little more than graphic violence to hold over what Dead Legs puts Maize through. His treatment of her is shocking, even 83 years later. Add dialogue to it, and this movie wouldn't seem out of place in the 1970s.
Lon Chaney's performance is astounding. He is more convincingly paralyzed than any other actor I've ever seen, even actors who have the benefit of computer graphics to make it seem as though their legs don't work. He is simultaneously one of the most depraved, monstrous men ever captured on film and a sympathetic character driven to evil by circumstances beyond his control.
If you've ever wondered how audiences sat through silent movies, just take a looks at West of Zanzibar, and realize that many more silent films just as good have been lost.