Below the battlefields of the Western Front, fifty thousand tunnellers, sewer workers, and miners were engaged in mine warfare in the Ypres Salient -- a secret struggle beneath No Man's Land that combined daring engineering, technology, and science with calculated assassination. Few on the surface knew of the barbaric and claustrophobic work of the tunnellers, who not only suffered from mine explosions but regularly encountered hazardous gas and waterlogged ground. The result of over twenty-five years of research, Beneath Flanders Fields reveals how this intense underground battle was fought and won.