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

Closer to victory...or closer to death? An army of darkness is on the march: Who won't escape with their life? The fourth book in the New York Times Bestselling TUNNELS series!At long last reunited with his dad, Will now spends his days exploring the "land of the second sun," decoding the cryptic glyphs carved into its three mysterious temples--or eyeing the wild animals with renegade girl Elliott. Chester, meanwhile, has finally returned Topsoil,...

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.