Book excerpt: A 1959 classic 'hard' science-fiction novel by renowned Cambridge astronomer and cosmologist Fred Hoyle. Tracks the progress of a giant black cloud that comes towards Earth and sits in front of the sun, causing widespread panic and death. A select group of scientists and astronomers - including the dignified Astronomer Royal, the pipe smoking Dr Marlowe and the maverick, eccentric Professor Kingsly - engage in a mad race to understand and communicate with the cloud, battling against trigger happy politicians. In the pacy, engaging style of John Wyndham and John Christopher, with plenty of hard science thrown in to add to the chillingly credible premise (he manages to foretell Artificial Intelligence, Optical Character Recognition and Text-to-Speech converters), Hoyle carries you breathlessly through to its thrilling end.