When his brother failed to return from a dangerous mission into the town dominated by Motils, Mathew knew that he must go after him.

it was not only a question of rescuing Don, but of finding out just how far the parasite rulers had advanced in their plans for bringing their master mind, the Controller, down to Earth. If the Controller arrived, the future of the human race would be even darker than its present.

It was not until Mathew made contact with a man who had been delivered from the power of the evil micro-organisms that he learned how close the Controller was, and just now imperative it was to strike a blow now.