When Richard Hannay is approached by the American military attach in London to carry out a delicate undercover mission, he immediately seeks out his old friend Sandy Arbuthnot. They meet at Sandy's country house in the Scottish Borders, but soon afterwards Sandy disappears in mysterious circumstances. As it turns out, these events are only the prelude to a dramatic series of adventures which take place against the backdrop of a small South American Republic that has fallen under the spell of a ruthless Dictator.

The Dictator is a powerful and charismatic leader, but he is also the mastermind behind a sinister international conspiracy that threatens the peace and security of the entire world. He has to be stopped, and Sandy Arbuthnot, master of disguise and born adventurer, is the man to do it, though revolution and war may be the price that has to be paid.