The Randolph family have a tradition of working in the British colonial service. Clive comes home from a mission in the Gold Coast of Africa accompanied by his wife Helen. He discovers his younger brother John, is not keen on following in his footsteps. John is then persuaded to try colonial service by his grandfather. He is accompanied by Clive who has been sent to investigate the source of a series of radio broadcasts that are sewing unrest throughout the world. These may be linked to Hugo Zurof, a man plotting to rule the world.

When cabinet minister John Hoode is murdered at his country house, his secretary, Alan Deacon, is the prime suspect and is arrested. Reporter Anthony Gethryn determines to unmask the real murderer.