'On Billabong station Jim, now assistant to his father, breaks in a promising young colt, and with Norah and Wally, helps with the intricacies of hauling a large bullock from the depths of a mud hole. World War I is underway. Jim and Wally want to enlist. Mr. Linton needs to travel to London on family business so they all set sail on the Perseus, a huge ocean liner carrying produce to Europe, to involve themselves in the war effort. On board they observe black-out restrictions to avoid being detected at night by enemy destroyers and deal physically with a German spy. They have an all too interesting time during their stopover in Durban, South Africa. Then their ship is captured by an enemy warship and almost sunk before a dramatic rescue takes place, allowing them to eventually reach London safely where the boys enlist in the British Army. ' (Publication summary)
