From publisher blurb:
It started only days after the invasion. Deep in the planet's interior, hidden from prying eyes, the caverns were created.
The caverns went down for miles, reaching to every corner of the Earth. Populated by creatures both kind and cruel, the tunnels grabbed Storm KnightsTM, pulling them into an underground realm of death.
The wonders of the underground world seemed endless: new civilizations, incredible treasures, and a dangerous passageway to a fringe reality. Only the bravest will survive the perils of the Land Below.
"However, all of the surprises of our subterranean journeys were nothing compared to the realization that deep in the core of the Earth was a realm where magic worked freely..." - Belladereth Dularent