The President's secret task force develops the ultimate defensive weapon. At its core: byzanium, a radioactive element so rare sufficient quantities have never been found. But a frozen American corpse on a desolate Soviet mountainside, a bizarre mining accident in Colorado, and a madman's dying message lead DlRK PITT to a secret cache of byzanium. Now he begins his most thrilling, daunting mission-- to raise from its watery grave the shipwreck of the century! In…