An experiment in German Expressionism, this 1923 silent, directed by the American-born Arthur Robison, was subtitled “A Nocturnal Hallucination” and released without intertitles. The story, a bit complicated to follow in pantomime, might have been cribbed from E.T.A. Hoffman. It seems that a young count (Fritz Kortner) jealous of his wife’s multiple admirers is driven by hocus-pocus to incite them to murder in the phantom zone. Self-reflexive as it is, Warning Shadows announces itself as a shadow play even before an itinerant showman (hyper-expressive Alexander Granach) performs one that hypnotizes his audience. Their spellbound shadows play out a violent catharsis that might be psychotherapy in the fifth dimension. Robison’s mise-en-scéne is appropriately artificial; the transfer has been made from a restored and color-tinted print.