Autumn is represented as a classic Victorian hero: honourable, perceptive and brave but out of his depth in a new age of ruthless exploitation personified by the bullish, cynical government official Dr. Davenport Spry.

After following the investigation across England and Scotland the pair, now accompanied by the drunk from London, discover that a single Martian has survived the bacteria by turning its own war machine into a hermetic chamber.

In return for its life - and human blood to sustain it, the alien dubbed "Humpty", has been assisting British scientists in mastering advanced Martian technical skills.

Later, a crippled and alcoholic Autumn witnesses the departure of Britain's Stellar Expeditionary Force to Mars, amid general scenes of patriotic fervor.

Thirty years after the events of Scarlet Traces, the counter-invasion of Mars is going badly, with the Martians successfully defending themselves using heat ray weapons against the invaders.

Charlotte Hemming, an aristocratic young photojournalist, is saved by Robert Autumn from the thuggish agents of an increasingly repressive British Government - led by Spry, now Prime Minister.

At the same time, the government is shown to be under pressure from a Nationalistic Scottish breakaway faction; plus Canada, Australia and New Zealand who wish to remove their troops from the space combat.

Spry's government is about to deliver a coup de grace in some unknown form, and destroy all the remaining Martians - as well as an expendable rearguard left behind when the main body of the expeditionary force is secretly evacuated.

The expected doomsday weapon is delivered, and turns out to be modified Cavorite in capsule form, which sticks to anything it touches, and lifts it off the planet into the vacuum of space.

Hemming is amongst those who survive, but they discover that humanoid Martians have taken control of the Lunar colony, and turned its mass driver into a weapon targeted on Earth.

Earth is saved, and the British government falls, with Spry being amongst those killed in the mass driver attacks which have devastated London and much of southern England.

[4] An official figure supervising the removal of Martian tripods after the end of the war resembles a young Dr. Spry, while the two army sergeants awaiting his orders reappear as Coughly and Dravott in Scarlet Traces.