January 1964. During a routine scan of the sky on Mount Palomar in California, an astronomer notices a strange black spot obscuring the stars. Further observation of an unidentified object brings disappointing news: a gaseous accumulation of unknown composition is moving towards the Sun at great speed. Information is carefully hidden from the population, but hard work is underway at the leadership level of the international community. A group of scientists from different countries gathers in the English town of Nortonstowe to assess the risks and develop a plan to save the planet from the threat of space.