Into a world armed to the teeth there suddenly comes a strange gospel of disarmament. The shedding of weapons has reached almost dangerous proportions, when it is realised that clever interplanetary trickery is to blame. Briefed to investigate the intrigue is Sidney Boyd of MI5, and from a murdered diplomat his adventures take him to the fantastic Earth Two, an exact duplicate of our own world in so far as living beings are concerned, and it falls to him - with the help of Orwena Exburg of Earth Two - to try and smash the deadly plan which is being matured against the peaceful nations of the world.