A harrowing novel which gives an Irish perspective on the Boer War

During the Second Boer War (1899-1902), in the course of Kitchener's notorious campaign against the civilian population, a junior officer witnesses a particularly brutal atrocity.

Disillusioned, and disgusted at himself for failing to intervene, he deserts. Ten years pass. On his return to Dublin under an assumed name, and battling an opium addiction, he discovers that the Major who ordered the atrocity is running for parliament. What should he do with his dangerous testimony? Will anybody believe the word of a deserter? And how to deal with the phantoms of the past that testimony will unleash?