Watch Brilliant Darkness: Hotaru in the Night (1970) : Full Movie Online Free 'Brilliant Darkness: Hotaru in the Night' explores the importance of darkness, and the erosion of it, through the study and preservation of firefly habitats in Japan and the United States. Fireflies are reportedly disappearing, as artificial night lights disrupt their 'languages of light'. 'Brilliant Darkness Hotaru in the Night', presented by the Zoological Lighting Institute, features artists and scientists on different continents working to understand firefly flash patterns and how to live among wildlife in urban settings.