"Having escaped to the Unknown Regions, Lina and the others seek help from the village people of Sparks"--Title verso page.

In "Underland," Macfarland delivers his masterpiece: 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...

"Wool introduced the world of the Silo. Shift told the story of its creation. Dust will describe its downfall. Juliette, now mayor of Silo 18, doesn't trust Silo 1, especially its leader, Donald. But in the world of the Silos, there is no black and white -- everything is shades of gray. Donald may not be the monster Juliette thinks he is, and may in fact be key to humanity's continued survival. But can they work together long enough to succeed?"--...

"The third pulse-pounding novel in an epic fantasy series set in the same world as the wildly popular Red Sister, following an outcast who will fight with everything she has to survive. On the harsh planet of Abeth, covered with ice except along a narrowcorridor, Yaz has had to fight hard to survive, and she's made friends-and enemies-along the way. The Convent of Sweet Mercy, like the Corridor itself, is packed with peril and opportunity. Yaz needs...

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.

"'I'm sorry,' I said, sure I hadn't heard her right. 'Do you mean you are still bringing dinosaurs back to life?' Were people really still resurrecting the creatures responsible for nearly wiping out the human race? Sky Mundy's life has changed dramatically since she fled the underground compound where she grew up. She and her friends are now prey to dinosaurs and being pursued by marines but Sky is determined to follow a map left by her missing father....

After seven hundred thousand years underground, a tribe emerges to a frozen Earth, in this novel from the Hugo and Nebula Award–winning author.
  The time of falling death stars ushered in the Long Winter—eons of cold that caused plants and animals to vanish from Earth and drove people to take refuge in underground cocoons. Human ingenuity had never faced a greater challenge. For seven hundred thousand years, generation...

Will Burrows believes he is safe at the very center of the earth, in a world that no one knows exists, but the Styx are close behind and will follow him anywhere, while on the surface, Drake and some unlikely allies unearth some critical secrets.

"Zachary Ezra Rawlins is a graduate student in Vermont when he discovers a rare book hidden in the stacks. As he turns the pages, entranced by tales of lovelorn prisoners, key collectors, and nameless acolytes, he reads something strange: a story from his own childhood. Bewildered by this inexplicable book and desperate to make sense of how his own life came to be recorded, Zachary uncovers a series of clues -- a bee, a key, and a sword -- that lead...

The ancient hidden city of Derinkuyu, Turkey, was forgotten for centuries until a man discovered a hidden wall while doing renovations on his home in 1963. Ancient Underground Structures uses cutaway illustrations to detail the hidden history of ancient structures, used by such people as troglodytes who inhabited underground churches, markets, mines, and burial chambers.