Armed with secret knowledge, Juliette, now mayor of Silo 18 and her crew set out to rescue a world she hates but now understands better -- the world of the Silos with its rigid rules and terrible consequences for disobedience.

"In the underground city of Caverna the world's most skilled craftsmen toil in the darkness to create delicacies beyond compare - wines that can remove memories, cheeses that can make you hallucinate and perfumes that convince you to trust the wearer, even as they slit your throat. The people of Caverna are more ordinary, but for one thing: their faces are as blank as untouched snow. Expressions must be learned, and only the famous Facesmiths can...

In Underland, Macfarland delivers an epic exploration of the Earth's underworlds -- as they exist in myth, literature, memory, and the land itself. He takes us on an extraordinary journey into our relationship with darkness, burial, and what lies beneath the surface of both place and mind. Traveling through "deep time" -- the dizzying expanses of geologic time that stretch away from the present -- he moves from the birth of the universe to a post-human...

"Behind a hole in their basement wall, Chirri and Chirra discover a network of tunnels. Join them as they visit moles, discover caves full of glowing flowers, poke at the roots of growing plants, traverse a subterranean lake, and spend the night with a family of badgers!" --

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.

When eleven-year-old Gregor and his two-year-old sister are pulled into a strange underground world, they trigger an epic battle involving men, bats, rats, cockroaches, and spiders while on a quest foretold by ancient prophecy.

On his way to dinner with his fiancee, Richard Mayhew helps a mysterious wounded girl lying on the sidewalk. The next day, he discovers his actions have erased him from existence and he is now consigned to the underground world of London Below.

When insane exile Corner and his army of mindless, whispering shadows invade Safe, a secret, underground community of freaks and disabled outcasts, Matthew, traumatized shapeshifter Ariel, and other misfits go to the dangerous place known as Above, where Matthew makes a shocking discovery about the histories entrusted to him.

As young archaeologist Will Burrows continues to search for his lost father in the strange underground world he has discovered beneath the city of London, he stumbles across a sinister plot with terrible implications for the world above.