Sunburn by Laura Lippman
They meet at a local tavern in the small town of Belleville, Delaware. Polly is set on heading west. Adam says he's also just passing through. Yet she stays. And he stays--drawn to the mysterious redhead whose quiet stillness both unnerves and excites him. Over the course of a punishing summer, Polly and Adam abandon themselves to a steamy, inexorable affair. Still, each holds something back from the other--dangerous, even lethal, secrets.
Then someone dies. Was it an accident, or part of a plan? By now, Adam and Polly are so ensnared in each other's lives and lies that neither one knows how to get away--or even if they want to. Is their love strong enough to withstand the truth, or will it ultimately destroy them?
Something--or someone--has to give.
"Fast-paced and unpredictable...a smart, sly riff on love in a world of trouble that's puzzling until the very last piece falls into place."