88 feet below Messines Ridge, an enormous charge of explosives lurks in the darkness, waiting to be detonated under the German trenches, whilst members of the Royal Irish Rifles prepare for the attack. Sapper John McCreesh entertains himself and his fellow miners with stories of the Morrigan, the war-goddess of the ancient Irish: stories which hold up a disturbing mirror to the lives of the men around him. Corry-Burnett, a young Lance-Corporal, must lead a trench raid in order to ascertain whether German miners are aware of the imminent danger, but one of his men is already a shell-shock victim whose conviction has been shaken by violence. Meanwhile, Siobhan O'Flaherty, a nursing sister, copes on a daily basis with the horrific injuries and psychological traumas of the victims of war. Her brooding, enigmatic presence and her strange connection with a pair of ravens will intrigue and mystify readers, as her feminine strength is mustered in a world dominated and traumatised by masculine power.