Memory Lost: Book 1 of The Memory Trilogy by Glori Medina

Book 1 of The Memory Trilogy In the planet Tatrax in the Dainne system, Cooper Hadley has made it to the top in his underground world. He’s the Security Chief of the Tunnel Corps as well as a Patrician, the most privileged class in the Kingdom. But when politics force him to marry, he needs a bride. The perfect candidate is Wye Botero—his one-time best friend. But Wye's a Drone, a member of the lowest class, and she has hated privileged Cooper for ten long years, ever since he threatened to have her recycled. Permanently. Wye is hiding a terrible secret about where her loyalties really lie. If she ends up in a fake marriage with the SecChief, what will happen when he finds out who she really works for? As the physical attraction between them grows, the two slowly learn to trust—but will it be too late? After all, the supernova is coming.