Watch Luna 13 for Free: How to Stream the Movie Online at 123Movies. . A few days after his grandfather's death, young Igor decides to make a documentary about the history of his family in an attempt to understand why his grandfather, Guilhermino, was obsessed with strange facts that had happened in his city. Thus, in 1990, in the interior of the state Rio Grande do Sul, Igor and his father Nilson interview relatives, friends and people involved in the case in an attempt to undo the bad name of his grandfather, but what they find out is a part of the story of the state, unraveling mysteries related to extraterrestrials, failed space programs and a muddled mission of the Cold War.