<p>On a drizzly evening in Tampa in 2006, 23-year-old Holly Jacobs was enjoying a typical date night with Ryan Seay, her boyfriend of a few short months. As the time to head home approached, he walked her to her car and reluctantly kissed her goodbye. She clung dreamily to the sweater Mr. Seay had given her earlier in the evening, when she’d said she was cold. As her car pulled out of Mr. Seay’s driveway, she noticed it: a little heart that he had traced in the raindrops collected on her rear windshield.</p>