When siblings Charlie and Mariah Cartwright stumble upon a mysterious tunnel in an abandoned mine on their family's property, they never imagined it would lead them to an entire underground city. Beneath the Earth, they discover New Breckenridge, a cyberpunk metropolis where sinister forces rule with an iron fist. As they navigate this strange and dangerous world, Charlie and Mariah uncover the dark truth behind the city's rulers-the Elite Society. But when they join forces with a brave band of rebels, the siblings soon find themselves at the heart of a battle for the city's very soul.