Cavemen kill fisherman in drunken mishap

There is nothing that reminds you what an incredibly diverse and secretive world we live in so much as when you discover a tribe of pre-neolithic xenophobes living on an island in the Indian Ocean - and they absolutely porcupine you with arrow. And your rescuers. These people have muddled through time since the stone age in complete isolation and there is nothing I don't find fascinating about this story.