One summer night, a falling star crosses the sky, describing a line of flame high in the atmosphere and leaving a glowing greenish streak in its wake. Early next morning, a huge cylinder is found half-buried on Horsell Common, hot from its journey through space. Under the eyes of a curious crowd, the cylinder's end begins to unscrew itself - and the tentacular creature within emerges... Earth is being invaded by Mars. Against the human tide of panic...