A heart-pounding rappel into the chasms of darkness.

Whitney Burke is a renowned cave researcher and marine biologist who has abandoned her livelihood after losing an assistant in a tragic caving accident. Though Whitney vows never to enter Labyrinth Cave again, her husband and daughter join a NASA-sponsored caving expedition.

When the expedition is overtaken by a group of criminals, Whitney must overcome her paralyzing fear to save her husband Tom, her daughter Cricket and, ultimately, herself.

Mark T. Sullivan's driving narrative explores the cave's terrifying subterranean atmosphere, a range of fascinating characters, and heart-stopping action sequences. Sullivan drops the reader into the story with force and momentum in this intensely told and adroitly crafted thriller, an astounding tale of adventure.