The flames in the title are by no means merely symbolic: they are the real flames of an Andean volcano in wild eruption. And it is in this hot, insane world of ashes, lava and earthquake that the business mission of Harold Dunnett, the young audit clerk, comes to sudden disaster. Sent out by his firm to investigate the suspicious trading affairs of Senior Muras, Mr. Dunnett, always very careful of his professional reputation, finds himself being drawn into a human jungle quite as impenetrable as the steamy jungle that lies outside Amricante. For one thing, the Amricante politicians are all businessmen, and some of the businessmen have politicians in their pockets: there is intrigue and corruption in the air. The books of the Compania Muras are mysteriously unobtainable: confidential cables go astray: key witnesses are missing. Mr. Dunnett himself is cajoled, offered bribes, warned and finally threatened. Throughout it all, however, he remains the perfect audit clerk, aloof and immaculate, vainly cabling his employers and writing affectionate letters to the nice little fiancée whom he left at home in England.
Then Senior Muras himself disappears up country and Mr. Dunnett, faithful in his purpose, goes in pursuit of him. At this point the local volcano blows its head off: all communications with the outside world are sundered. In his desperate pursuit Harold finds himself involved not only in a local war, but with Carmel Muras, the beautiful daughter of Senior Muras. Together they experience danger and disaster.