Fire balls fill the London skies, frightened crowds run from sheets of flame. People in shiny plastic suits stroke their chins at the HQ of the Scientific Research Society and look at lights flickering on a screen. The fire balls have a pattern. London's population is evacuated as fire fighters struggle with the great fire. Twisted metal is recovered from the fires the likes of which never seen before in the world.
Egg heads do lots of work and determine the fire balls come from Mars.
Captain Jim Holly is the man for the job, jutting jaw just the right sort of shape for squeezing into a bell jar. A fire ball is spotted by 'Nobby' and atom guns blast the beast into fragments which continue towards earth. Fragments of fireball are examined to find complex guidance systems. Time for Jim to take the fight to Mars. The new strato battle cruiser is needed for the job.