This novel traces the adventures of a young man, Dragan Kelly (Dan) who, at times and often against his will, gradually becomes immersed in espionage. The action takes place during and just after the second world war.
After being shipwrecked off Norway he is looked after by Sybilla and her husband, both members of a Norwegian underground movement. He falls hopelessly in love with the enigmatic Sybilla, despite her already having a German lover.
Kelly escapes to Russia after gathering information on a heavy water plant. However he is treated more as a criminal than an ally.
After returning home he makes the acquaintance of a high ranking navel office who will have a significant impact on his future. Kelly is persuaded to train as a commando and later takes part in the disastrous Dieppe raid but, his courage and initiative are noted and as a consequence he is selected to take part in a daring raid on the heavy water plant in Norway.
The raid goes well, but he is devastated to find that some of his Norwegian friends have been killed by the Gestapo. Sybilla, it appears has fled Norway with her German lover. What follows is a sequence of events that sees him drawn inextricably into the dark world of espionage, whilst at the same time he continues his relentless search for the beautiful Sybilla. .