Leading Seaman Albert Brown is the son of Agatha Brown, a middle-class religiously brought-up woman who conceives him as a result of a five-day fling in 1897 with a young naval officer, Lieutenant-Commander Richard Saville-Samarez. Agatha is resourceful, and as she has her own income she is able to leave her disapproving family and take lodgings, where she represents herself as a widow.
She brings up Albert to believe that it is his duty to join the Navy, which he does after his mother's early death. He is posted to HMS Charybdis and at the outbreak of the first world war he finds himself in the Pacific. His ship is sunk in a battle with the German cruiser Ziethun; there are only three survivors, of whom he is one (the others are severely wounded).
Ziethun was holed beneath the waterline in the battle and her captain decides to take her into the natural harbour of Resolution to effect repairs. While these are going on Brown slips over the side with a rifle and ammunition and swims to the shore, where he establishes himself on a vantage point overlooking the ship. He shoots numerous Germans, both those carrying out the repairs and others who are sent in a landing party to capture or kill him. In this way he delays the departure of the ship for 48 hours—long enough for a British battle cruiser to arrive and sink her as she is leaving the island.
Brown has been wounded by a lucky shot from one of the landing party and dies soon after the departure of the German ship. He knows nothing of her fate and thinks he has failed. The irony of the situation is compounded by the fact that the captain of the British cruiser is his father, Samarez, who never knew of his son's existence.
The novel provides a picture of Edwardian life and mores in its first part as well as plenty of vividly described action in its second part. The writing is itself rather Edwardian at times—a little stilted—and there is a lot of historical exposition of the naval strategy of the war that the later Forester of the Hornblower series would have managed better. But apart from this the book certainly holds one's attention.