The narrative opens in an astronomical observatory at Ottershaw where explosions are seen on the surface of the planet Mars, creating much interest in the scientific community. Later a "meteor" lands on Horsell Common, near the unnamed narrator's home in Woking, Surrey. He is among the first to discover that the object is an artificial cylinder that opens, disgorging Martians who are "big" and "greyish" with "oily brown skin", "the size, perhaps, of a bear", each with "two large dark-coloured eyes", and lipless "V-shaped mouths" which drips saliva and are surrounded by two "Gorgon groups of tentacles".

The narrator finds them "at once vital, intense, inhuman, crippled and monstrous".

They briefly emerge, have difficulty in coping with the Earth's atmosphere, rapidly retreating into their cylinder. A human deputation (which includes the astronomer Ogilvy) approaches the cylinder with a white flag, but the Martians incinerate them and others nearby with a Heat-Ray before beginning to assemble their machinery. Military forces arrive that night to surround the common, including Maxim guns. The population of Woking and the surrounding villages are reassured by the presence of the military. A tense day begins, with much anticipation of military action by the narrator.