The book tells the story of an infantry officer on the Western Front from 1915-1918. For the majority of this time the writer was in the Fourth Battalion of the Coldstream Guards, which had been designated as a "pioneer" battalion keeping open the lines of communications. As they were not called upon to 'go over the top', , their casualties were lighter than those of other battalions. This so preyed on the author's conscience he applied for, and was granted, a transfer to the Second Battalion. He was wounded in September 1918, and was hospitalised for three weeks. By the time he rejoined his battalion, the Germans were in full retreat, and the book ends with a moving description of the liberation of French towns which had been under German occupation for fours years.

The book differs from others of this genre by virtue of several features: the writer's introspective reflections on the traumatic events in which be was involved; his shrewd character sketches of his fellow officers; his strange mystical experience on the banks of the River Somme; the poignant juxtaposition of desolation wreaked by the war and his intense love of natural history, particularly birds and wild flowers. Above all he believed that the whole war was a hideous mistake.