A rat called Crocus, imprisoned in the laboratory of an Irish scientist Dr Dresmond Burke, is transmitting information to a person or persons unknown in another galaxy. His information is in the form of a report on man's history and development over the past 500 years. And it ends with Crocus's shadowy imprecise foreknowledge of what will become of the human race in the future.

Crocus is sharp, wise and cleverer by far than most men - as, he claims, the whole race of rats is. He comments astutely on man's spiritual decline; on the collapse of formalised religion and the obsession with things scientific; with man's mistakes in numerology, and therefore in mathematics and astronomy; and with his loss of faith in all that is supernatural or extra-sensory. But Crocus himself is being monitored by Dr Burke, who is beaming the rat's thoughts through an elderly lady medium and on to a tape recorder. The message as transmitted is unintelligible, but Dr Burke thinks he knows a way to interpret it. This involves outside help...the help of the army...of foreign powers. And then he discovers that what he has learned through Crocus is already known to a small band of resolute and dedicated men. Man's thought-processes can be interfered with, thought-waves can move material objects, and this knowledge is being put to a use more potent than the nuclear bomb...