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The narrator asks readers not to judge the Martians too harshly, since Europeans had themselves wiped out the Tasmanians and destroyed the bison and the dodo in a war of extermination. Casting the English as the colonized forces a dominant culture to experience its own methods from the receiving end. What seemed like civilization's progress from the inside appears as extermination from the outside.
Martian cylinders land near Woking in Surrey. The Martians use tripod fighting-machines, a Heat-Ray and poisonous Black Smoke to crush the British army and empty London. Then they suddenly die, killed by terrestrial bacteria their bodies had no defence against, and the narrator finds them silent and rotting on Primrose Hill.
Humans survive microbes because countless ancestors died of them, leaving a population selected for resistance. The Martians, from a world without such germs, had superior weapons but no evolved immunity, and they fell to the smallest organisms on Earth. Belonging to an environment is paid for in deaths across generations, and technology cannot buy that adaptation.
The book opens with humanity going about its business, 'serene in their assurance of their empire over matter', while minds on Mars study it the way a person studies creatures in a drop of water. The confidence of being at the top of a hierarchy stops the powerful from imagining a stronger observer. That is why the first cylinder draws curious crowds rather than alarm.