A double murder sparks this incredibly powerful 18th Century drama, set in the wild and beautiful Peak District of Derbyshire. Here Joanna Royce is growing up in the lead mining community, where her parents eke out a back-breaking existence, dreaming of the breakthrough which will change their fortunes. But the family's fate is about to be changed in a quite different way, when a wealthy young honeymoon couple disappears and suspicion falls on Joanna's father, just as her own discovery of the first rare, semi-precious stone known as Blue John, holds out the promise of a better life. Is he guilty? And if he is, can Joanna ever escape the drudgery that has seemed to be her birthright? She knows that she must find out the truth of what happened on that dark night on Winnats Pass - painful and terrifying although that truth may be.