Pandemonium

Deep beneath the Ural Mountains, in an underground city carved out by slave labor during the darkest hours of the Cold War, ancient caverns hold exotic and dangerous life-forms that have evolved in isolation for countless millennia. Cut off from the surface world, an entire ecosystem of bizarre subterranean species has survived undetected—until now. Biologists Nell and Geoffrey Binswanger barely survived their last encounter with terrifying, invasive creatures that threatened to engulf the planet. They think the danger is over until a ruthless Russian tycoon lures them to his underground metropolis, where they find themselves confronted by a vicious menagerie of biological horrors from their past—and by entirely new breeds of voracious predators. Now they're rising up from the bowels of the Earth to consume the world as we know it.