A post apocalyptic story written in 1922, before the atomic bomb, but in every way anticipating the post apocalyptic SF stories and films we're familiar with from the post WW2 period, religious renunciation of knowledge, savage survival etc. It shows that, to the sensitive, the advent of modern ideas occurred in the shock of industrial war in WW1. Some of its ideas about using mass displacement of people anticipates WW2, interesting but not very cheerful.