The Threat Below

Three hundred years ago, something arose and pushed humanity to the brink of extinction. Now, a small remnant – the ancestors of the few survivors who were able to escape the massacre below – lives above the clouds, on the top of a mountain. But there's been a change. Their water supply is being poisoned. Someone, or something down below is trying to kill them. Now an expedition, including seventeen year-old girl Icelyn Brathius, must descend and face the monsters that wiped out civilization centuries ago.