When Will Burrows and his friend Chester embark on a quest to find Will's archaeologist father, who has inexplicably disappeared, they are led to a labyrinthine world underneath London, full of sinister inhabitants with evil intentions toward "Topsoilers" like Will and his father.

Life becomes more interesting for Ananka Fishbein when, at the age of twelve, she discovers an underground room in the park across from her New York City apartment and meets a mysterious girl called Kiki Strike who claims that she, too, wants to explore the subterranean world.

"A generation ago, continent-sized storms called hypercanes caused the Earth to flood. The survivors were forced to retreat deep underground and build a new society. This is the story that sixteen-year-old Jansin Nordqvist has heard all of her life. Jansin grew up in the civilization far below the Earth's surface. She's spent the last eight years in military intelligence training. So when her parents surprise her with a coveted yet treacherous trip...