Tuck and Emily grew up together in their neighboring California orange groves and nearly gave their hearts to each other, but life pulled them apart and set them on very different paths. Now, 13 years later, stubborn, sunny Emily is a pop star and brooding Tuck is an ex-con in need of a job. When Emily hires him to be her bodyguard, they naturally butt heads, even as both try to ignore the heat rekindling between them.   When a massive solar flare hits Earth, knocking out the electrical grid and all satellites, the world changes forever instantly. Tuck and Emily are forced to come together to fight for their lives and find a new place in this post-apocalyptic world—one where everything Emily has worked so hard for has crumbled, but also one where Tuck can start over and maybe even thrive.   Heart of the Sun is a bullseye Mia Sheridan new adult romance with a post-apocalyptic backdrop that tests the characters to be their better selves.