The story is set in the Austro-Hungarian Navy during World War I, and vividly depicts life on board the primitive and dangerous U-boats of the period.

[2] The Historical Novel Society, on the other hand, deemed it "Excellent military fiction", and similarly praised his later book Tomorrow The World.

This novel was included by The Spectator magazine on its "Books of the Year" list,[4] described as a "soundly researched tale of sea-faring and warfare."

Ottokar Prohaska, the fictional protagonist, is a Czech by birth, but an Austrian naval officer by vocation.

[5] The reader finds the hero/anti-hero, at different times, a gunnery officer aboard a ship, a submarine commander, and a member of the flying corps.