Watch Nightfall for Free: How to Stream the Movie Online at 123Movies. . The people of the planet Aeon, blessed with six suns, have never experienced night. When an archeological excavation uncovers evidence of an ancient catastrophe, all signs point towards the impending darkness of the very first Nightfall. Panic erupts as the suns slowly disappear one by one. Science struggles against superstition as the people race to comprehend the approaching Nightfall... the end of the world as they know it. Based on Isaac Asimov's classic story "Nightfall," voted "The Greatest Science-Fiction Story OF All Time."