an up-too-close-and-personal encounter between underwater photographer Valerie De La Valdene and a nasty school of the predators. "Primal Scream" explores the nature of sharks and of human fear using De La Valdene's footage, interviews with experts and a trip to the Galapagos waters, the site of De La Valdene's near-death experience. In addition to De La Valdene's underwater chiller, "Primal Scream" - the first of the seven all-new Shark Week installments - also previews the upcoming big-screen thriller "Open Water".