Although the overall plot is obvious, the details are baffling; characters have dreams/visions/hallucinations that are never explained; most exposition parts seem to have been cut out; the film moves from one warped scene to another instead of trying to build some atmosphere. Robert Vaughn is utterly unconvincing in the first half of the film (though he improves later on), and Donald Pleasence is irritating as the doctor/possible suspect who mostly comes across as just a senile old man. (*1/2)