One of the sexiest scenes I've ever read in a novel can be found in Free Fire , a mystery by C.J. Box. In it, Wyoming game warden Joe Pickett teams with Judy Demming, a National Park Service ranger, to investigate a killing in Yellowstone National Park. Pickett, as usual, is away from home, which has been causing problems between him and his wife. Demming is bored with her job and her husband. The spouses are both good people, and their partners love them, but they are largely offstage while Pickett and Demming bond during their travels through the park. Their shared career frustrations, and clear respect for each other's investigative acumen, lead to a subtly crackling chemistry that neither wants to acknowledge and yet cannot deny. In a painful, halting moment, they express unwilling vulnerability toward one another — and then mutually decide, with no small regret, that no physical lines will be crossed. So nothing happens. And yet, everything happens. I remember r...