Isabel Aird is aghast when her husband is appointed doctor to an extraordinary waterworks being built miles from the city. But Isabel following a succession of miscarriages finds unexpected consolations in a place where she can feel the presence of her unborn children and begin to work out what her life in Victorian society is for. The hills echo with the gunpowder blasts of hundreds of navvies tunnelling to bring clean water to diseased Glasgow thirty miles away - digging so deep that there are those who worry they are disturbing the land of faery itself. With new life quickening within her again Isabel can only wait. But a darker presence has also emerged from the gunpowder smoke. . .