Put Out More Flags is set during the first year of the war and follows the wartime activities of characters introduced in Waugh’s earlier satirical novels Decline and Fall, Vile Bodies, and Black Mischief.

The dormant conflict is reflected in the activity of the novel’s main characters. Earnest would-be soldier Alistair Trumpington finds himself engaged in incomprehensible manoeuvres instead of real combat, while Waugh’s recurring ne’er-do-well Basil Seal, finds ample opportunity for amusing himself in the name of the war effort.

A successful, middle-aged novelist with a case of 'bad nerves,' Gilbert Pinfold embarks on a recuperative trip to Ceylon. Almost as soon as the gangplank lifts, Pinfold hears sounds coming out of the ceiling of his cabin: wild jazz bands, barking dogs, loud revival meetings. He can only infer that somewhere concealed in his room an erratic public-address system is letting him hear everything that goes on aboard ship. And then, instead of just sounds, he hears voices. But they are not just any voices. These voices are talking, in the most frightening intimate way, about him!