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.