The Midnight Line (Jack Reacher 22) | Lee Child

Jack Reacher takes an aimless stroll past a pawn shop in a small Midwestern town. In the window he sees a West Point class ring from 2005. Reacher's a West Pointer too, and he knows what she went through to get it. Reacher tracks the ring back to its owner, step by step, down a criminal trail leading west. If she's OK, he'll walk away.