描述
In 1964, astrophysicists become aware that an immense gas cloud is entering the solar system. The cloud, moving to interpose itself between the sun and the earth, has the potential to wipe out most of the life on the earth by blocking solar radiation and thus ending photosynthesis. A cadre of astronomers and other scientists assemble in Nortonstowe, England, to study the cloud and report to the British government about the consequences of its presence.