The midnight line

Reacher rides the bus north from Milwaukee. At a comfort stop in Wisconsin dairy country he takes a stroll. Among the cheap junk in a pawn shop window he notices a West Point class ring for sale. It's tiny. A woman cadet's ring. Why would she pawn it? Reacher knows what Serena Sanderson must have gone through to get it. He fights through a biker gang and a South Dakota gangster, following the trail of the ring to the emptiness of Wyoming, in search of Major Sanderson. Is she OK?.