The Last Wave (1977) or Black Rain by Peter Weir
Since I love Weir's previous film 'Picnic at Hanging Rock', I watched this last night. It's about an Australian lawyer (Richard Chamberlain) who has to defend five Aborigines accused of murdering one of their own in something that suspiciously looks like a ritual. But, then, a lawyer starts having some weird dreams and feeling a mystical connection to Aborigines and their mythology. A good film overall, but 'Picnic at Hanging Rock' was much better, although they share similar themes.