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.

"Styx and their cohorts of deadly Armagi have swept across England, leaving death and devastation in their wake. Only a miracle can save the day and, in the inner world at the centre of the earth, Will and Elliott might just have stumbled upon one as they uncover ancient secrets that are fundamental to all human and Styx life"--

Teenager Eliza and her friends are going to explore a cave near their upstate New York home, but first her friends insist on dragging her to Drowner's Swamp, a bog legendary for its dangerous sinkholes, and a place which her mother has frequently warned her about; Eliza does not want to go, and when the earth opens up and swallows her she finds herself in a system of caves--and what she finds living there is strange and dangerous beyond anything the...