When a group of friends rent a converted farmhouse in the Yorkshire Dales, they have little idea that this one weekend may change the course of their lives forever. While out on a walk, a storm descends and the friends take shelter in the mouth of an old lead mine. Inside, they discover a backpack filled with more money than they've ever seen.

Of course, they agree, they will hand the money to the police at the first opportunity. But as the storm continues and time passes, some of the party begin to think again. Because there are secrets festering at the heart of this group.

Problems that could be solved instantly with an unexpected windfall. And perhaps they don't know each other as well as thought they did. Before long, six good friends find themselves sliding headlong into a world of deceit, treachery, betrayal and murder.